Invasion of Poland (1939)
Overview
 
The Invasion of Poland, also known as the September Campaign or 1939 Defensive War (Polish
Polish language
Polish is a language of the Lechitic subgroup of West Slavic languages, used throughout Poland and by Polish minorities in other countries...

: Kampania wrześniowa or Wojna obronna 1939 roku) in Poland
Second Polish Republic
The Second Polish Republic, Second Commonwealth of Poland or interwar Poland refers to Poland between the two world wars; a period in Polish history in which Poland was restored as an independent state. Officially known as the Republic of Poland or the Commonwealth of Poland , the Polish state was...

 and the Poland Campaign (German
German language
German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....

: Polenfeldzug) in Germany, was an invasion of Poland by Germany
Nazi Germany
Nazi Germany , also known as the Third Reich , but officially called German Reich from 1933 to 1943 and Greater German Reich from 26 June 1943 onward, is the name commonly used to refer to the state of Germany from 1933 to 1945, when it was a totalitarian dictatorship ruled by...

, the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

, and a small Slovak
Slovak invasion of Poland (1939)
The Slovak invasion of Poland occurred during Nazi Germany's invasion of Poland in 1939. The recently-created Slovak Republic joined the attack, and the Slovak field army contributed over 50,000 soldiers in three divisions...

 contingent that marked the start of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

. The invasion began on 1 September 1939, one week after the signing of the Molotov–Ribbentrop Pact, and ended on 6 October 1939 with Germany and the Soviet Union dividing and annexing the whole of Poland.

The morning after the Gleiwitz incident
Gleiwitz incident
The Gleiwitz incident was a staged attack by Nazi forces posing as Poles on 31 August 1939, against the German radio station Sender Gleiwitz in Gleiwitz, Upper Silesia, Germany on the eve of World War II in Europe....

, German forces invaded Poland from the north, south, and west.
Encyclopedia
The Invasion of Poland, also known as the September Campaign or 1939 Defensive War (Polish
Polish language
Polish is a language of the Lechitic subgroup of West Slavic languages, used throughout Poland and by Polish minorities in other countries...

: Kampania wrześniowa or Wojna obronna 1939 roku) in Poland
Second Polish Republic
The Second Polish Republic, Second Commonwealth of Poland or interwar Poland refers to Poland between the two world wars; a period in Polish history in which Poland was restored as an independent state. Officially known as the Republic of Poland or the Commonwealth of Poland , the Polish state was...

 and the Poland Campaign (German
German language
German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....

: Polenfeldzug) in Germany, was an invasion of Poland by Germany
Nazi Germany
Nazi Germany , also known as the Third Reich , but officially called German Reich from 1933 to 1943 and Greater German Reich from 26 June 1943 onward, is the name commonly used to refer to the state of Germany from 1933 to 1945, when it was a totalitarian dictatorship ruled by...

, the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

, and a small Slovak
Slovak invasion of Poland (1939)
The Slovak invasion of Poland occurred during Nazi Germany's invasion of Poland in 1939. The recently-created Slovak Republic joined the attack, and the Slovak field army contributed over 50,000 soldiers in three divisions...

 contingent that marked the start of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

. The invasion began on 1 September 1939, one week after the signing of the Molotov–Ribbentrop Pact, and ended on 6 October 1939 with Germany and the Soviet Union dividing and annexing the whole of Poland.

The morning after the Gleiwitz incident
Gleiwitz incident
The Gleiwitz incident was a staged attack by Nazi forces posing as Poles on 31 August 1939, against the German radio station Sender Gleiwitz in Gleiwitz, Upper Silesia, Germany on the eve of World War II in Europe....

, German forces invaded Poland from the north, south, and west. As the Germans advanced, Polish forces withdrew from their forward bases of operation close to the Polish-German border to more established lines of defence to the east. After the mid-September Polish defeat in the Battle of the Bzura
Battle of the Bzura
The Battle of the Bzura was a battle in the opening campaign of World War II during the 1939 German invasion of Poland, fought between 9 and 19 September, 1939, between Polish and German forces...

, the Germans gained an undisputed advantage. Polish forces then withdrew to the southeast
Plan West
Plan Zachód was a military plan of the Polish Army of the Second Polish Republic, for defence against invasion from Nazi Germany. It was designed in the late 1930s.-Background:...

 where they prepared for a long defence of the Romanian Bridgehead
Romanian Bridgehead
The Romanian Bridgehead was an area in southeastern Poland, now located in Ukraine. During the Polish Defensive War of 1939 , on September 14 the Polish Commander in Chief Marshal of Poland Edward Rydz-Śmigły ordered all Polish troops fighting east of the Vistula to withdraw towards Lwów, and...

 and awaited expected support and relief from France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 and the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

. The two countries had pacts with Poland and had declared war on Germany on 3 September, though in the end their aid to Poland in the September campaign was very limited.

The Soviet Red Army
Red Army
The Workers' and Peasants' Red Army started out as the Soviet Union's revolutionary communist combat groups during the Russian Civil War of 1918-1922. It grew into the national army of the Soviet Union. By the 1930s the Red Army was among the largest armies in history.The "Red Army" name refers to...

's invasion
Soviet invasion of Poland
Soviet invasion of Poland can refer to:* the second phase of the Polish-Soviet War of 1920 when Soviet armies marched on Warsaw, Poland* Soviet invasion of Poland of 1939 when Soviet Union allied with Nazi Germany attacked Second Polish Republic...

 of Eastern Poland
Kresy
The Polish term Kresy refers to a land considered by Poles as historical eastern provinces of their country. Today, it makes western Ukraine, western Belarus, as well as eastern Lithuania, with such major cities, as Lviv, Vilnius, and Hrodna. This territory belonged to the Polish-Lithuanian...

 on 17 September, in accordance with a secret protocol of the Molotov–Ribbentrop Pact, rendered the Polish plan of defence obsolete. Facing a second front, the Polish government concluded the defence of the Romanian Bridgehead was no longer feasible and ordered an emergency evacuation of all troops to neutral Romania
Romania
Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...

. On 6 October, following the Polish defeat at the Battle of Kock
Battle of Kock (1939)
The Battle of Kock, was the final battle in the Invasion of Poland at the beginning of World War II. It took place between 2–5 October 1939, near the town of Kock, in Poland....

, German and Soviet forces gained full control over Poland. The success of the invasion marked the end of the Second Polish Republic
Second Polish Republic
The Second Polish Republic, Second Commonwealth of Poland or interwar Poland refers to Poland between the two world wars; a period in Polish history in which Poland was restored as an independent state. Officially known as the Republic of Poland or the Commonwealth of Poland , the Polish state was...

, though Poland never formally surrendered.

On 8 October, after an initial period of military administration
German military administration in occupied Poland
German military administration in occupied Poland refers to the brief period during and in the immediate aftermath of the German invasion of Poland , in which the occupied Polish territories were administered by the German military, instead of civilian, administration.-Military administration:On 8...

, Germany directly annexed
Polish areas annexed by Nazi Germany
At the beginning of World War II, nearly a quarter of the pre-war Polish areas were annexed by Nazi Germany and placed directly under German civil administration, while the rest of Nazi occupied Poland was named as General Government...

 western Poland and the former Free City of Danzig
Free City of Danzig
The Free City of Danzig was a semi-autonomous city-state that existed between 1920 and 1939, consisting of the Baltic Sea port of Danzig and surrounding areas....

 and placed the remaining block of territory under the administration of the newly established General Government
General Government
The General Government was an area of Second Republic of Poland under Nazi German rule during World War II; designated as a separate region of the Third Reich between 1939–1945...

. The Soviet Union incorporated its newly acquired areas into its constituent Belarusian and Ukrainian republics
Ukrainian SSR
The Ukrainian Soviet Socialist Republic or in short, the Ukrainian SSR was a sovereign Soviet Socialist state and one of the fifteen constituent republics of the Soviet Union lasting from its inception in 1922 to the breakup in 1991...

, and immediately started a campaign of sovietization
Sovietization
Sovietization is term that may be used with two distinct meanings:*the adoption of a political system based on the model of soviets .*the adoption of a way of life and mentality modelled after the Soviet Union....

. This included staged elections, the results of which were used to legitimize the Soviet Union's annexation of eastern Poland. In the aftermath of the invasion, a collective of underground resistance organizations
Polish resistance movement in World War II
The Polish resistance movement in World War II, with the Home Army at its forefront, was the largest underground resistance in all of Nazi-occupied Europe, covering both German and Soviet zones of occupation. The Polish defence against the Nazi occupation was an important part of the European...

 formed the Polish Underground State within the territory of the former Polish state. Many of the military exiles that managed to escape Poland subsequently joined the Polish Armed Forces in the West
Polish Armed Forces in the West
Polish Armed Forces in the West refers to the Polish military formations formed to fight alongside the Western Allies against Nazi Germany and its allies...

, an armed force loyal to the Polish government in exile
Polish government in Exile
The Polish government-in-exile, formally known as the Government of the Republic of Poland in Exile , was the government in exile of Poland formed in the aftermath of the Invasion of Poland of September 1939, and the subsequent occupation of Poland by Nazi Germany and the Soviet Union, which...

.

Prelude to the campaign

In 1933, the National-Socialist German Workers' Party—under its leader Adolf Hitler
Adolf Hitler
Adolf Hitler was an Austrian-born German politician and the leader of the National Socialist German Workers Party , commonly referred to as the Nazi Party). He was Chancellor of Germany from 1933 to 1945, and head of state from 1934 to 1945...

—came to power in Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

. Germany sought to gain hegemony
Hegemony
Hegemony is an indirect form of imperial dominance in which the hegemon rules sub-ordinate states by the implied means of power rather than direct military force. In Ancient Greece , hegemony denoted the politico–military dominance of a city-state over other city-states...

 in Europe, and to take over territory from the Soviet Union, acquiring "Living Space" (Lebensraum
Lebensraum
was one of the major political ideas of Adolf Hitler, and an important component of Nazi ideology. It served as the motivation for the expansionist policies of Nazi Germany, aiming to provide extra space for the growth of the German population, for a Greater Germany...

) and expanding "Greater Germany" (Großdeutschland), and to fulfill their age-long goal that has so long eluded them- to conquer the unconquerable- Poland. Also to be eventually surrounded by a ring of allied states, satellite
Satellite state
A satellite state is a political term that refers to a country that is formally independent, but under heavy political and economic influence or control by another country...

 or puppet state
Puppet state
A puppet state is a nominal sovereign of a state who is de facto controlled by a foreign power. The term refers to a government controlled by the government of another country like a puppeteer controls the strings of a marionette...

s. As part of this long term policy, at first, Hitler pursued a policy
Policy
A policy is typically described as a principle or rule to guide decisions and achieve rational outcome. The term is not normally used to denote what is actually done, this is normally referred to as either procedure or protocol...

 of rapprochement
Rapprochement
In international relations, a rapprochement, which comes from the French word rapprocher , is a re-establishment of cordial relations, as between two countries...

 with Poland, trying to improve German–Polish relations
German–Polish relations
German–Polish relations have a long and complicated history. From the 10th century on, the Kingdom of Poland had relations with the Holy Roman Empire, which were however soon overshadowed by the Polish-Teutonic wars, as a result of which, Prussia became a fief of the Kingdom of Poland. Prussia...

, culminating in the German–Polish Non-Aggression Pact of 1934. Earlier, Hitler's foreign policy worked to weaken the ties between Poland and France, and to manoeuvre Poland into the Anti-Comintern Pact
Anti-Comintern Pact
The Anti-Comintern Pact was an Anti-Communist pact concluded between Nazi Germany and the Empire of Japan on November 25, 1936 and was directed against the Communist International ....

, forming a cooperative front against the Soviet Union. Poland would be granted territory of its own, to its northeast, but the concessions the Poles were expected to make meant that their homeland would become largely dependent on Germany, functioning as little more than a client state. The Poles feared that their independence would eventually be threatened altogether.

In addition to Soviet territory, the National-Socialists were also interested in establishing a new border with Poland because the German exclave of East Prussia
East Prussia
East Prussia is the main part of the region of Prussia along the southeastern Baltic Coast from the 13th century to the end of World War II in May 1945. From 1772–1829 and 1878–1945, the Province of East Prussia was part of the German state of Prussia. The capital city was Königsberg.East Prussia...

 was separated from the rest of the Reich by the "Polish Corridor
Polish Corridor
The Polish Corridor , also known as Danzig Corridor, Corridor to the Sea or Gdańsk Corridor, was a territory located in the region of Pomerelia , which provided the Second Republic of Poland with access to the Baltic Sea, thus dividing the bulk of Germany from the province of East...

". The Corridor constituted land long disputed by Poland and Germany, and inhabited by both groups. The Corridor became a part of Poland after the Treaty of Versailles
Treaty of Versailles
The Treaty of Versailles was one of the peace treaties at the end of World War I. It ended the state of war between Germany and the Allied Powers. It was signed on 28 June 1919, exactly five years after the assassination of Archduke Franz Ferdinand. The other Central Powers on the German side of...

. Many Germans also wanted the city of Danzig
Gdansk
Gdańsk is a Polish city on the Baltic coast, at the centre of the country's fourth-largest metropolitan area.The city lies on the southern edge of Gdańsk Bay , in a conurbation with the city of Gdynia, spa town of Sopot, and suburban communities, which together form a metropolitan area called the...

 and its environs (together the Free City of Danzig
Free City of Danzig
The Free City of Danzig was a semi-autonomous city-state that existed between 1920 and 1939, consisting of the Baltic Sea port of Danzig and surrounding areas....

) to be reincorporated into Germany. Danzig was an important port city with 95% of the population German speakers. It had been separated from Germany after Versailles and made into a nominally independent Free City of Danzig. Hitler sought to reverse these territorial losses, and on many occasions made an appeal to German nationalism
Nationalism
Nationalism is a political ideology that involves a strong identification of a group of individuals with a political entity defined in national terms, i.e. a nation. In the 'modernist' image of the nation, it is nationalism that creates national identity. There are various definitions for what...

, promising to "liberate" the German minority
German minority in Poland
The registered German minority in Poland consists of 152,900 people, according to a 2002 census.The German language is used in certain areas in Opole Voivodeship , where most of the minority resides...

 still in the Corridor, as well as Danzig.

Poland participated in the partition of Czechoslovakia
German occupation of Czechoslovakia
German occupation of Czechoslovakia began with the Nazi annexation of Czechoslovakia's northern and western border regions, known collectively as the Sudetenland, under terms outlined by the Munich Agreement. Nazi leader Adolf Hitler's pretext for this effort was the alleged privations suffered by...

 that followed the Munich Agreement
Munich Agreement
The Munich Pact was an agreement permitting the Nazi German annexation of Czechoslovakia's Sudetenland. The Sudetenland were areas along Czech borders, mainly inhabited by ethnic Germans. The agreement was negotiated at a conference held in Munich, Germany, among the major powers of Europe without...

, although they were not part of the agreement. It coerced Czechoslovakia to surrender the region of Český Těšín
Ceský Tešín
Český Těšín is a town in the Karviná District, Moravian-Silesian Region of the Czech Republic. The town is commonly known in the region as just Těšín . It lies on the west bank of the Olza River, in the heart of the historical region of Cieszyn Silesia...

 by issuing an ultimatum to that effect on 30 September 1938, which was accepted by Czechoslovakia on 1 October.

By 1937, Germany began to increase its demands for Danzig, while proposing that a roadway be built in order to connect East Prussia with Germany proper, running through the Polish Corridor. Poland rejected this proposal, fearing that after accepting these demands, it would become increasingly subject to the will of Germany and eventually lose its independence as the Czechs had. Polish leaders also distrusted Hitler. Furthermore, Germany's collaboration with anti-Polish Ukrainian nationalists from the Organization of Ukrainian Nationalists
Organization of Ukrainian Nationalists
The Organization of Ukrainian Nationalists is a Ukrainian political organization which as a movement originally was created in 1929 in Western Ukraine . The OUN accepted violence as an acceptable tool in the fight against foreign and domestic enemies particularly Poland and Russia...

, which was seen as an effort to isolate and weaken Poland, weakened Hitler's credibility from the Polish point of view. The British were also aware of the situation between Germany and Poland. On 31 March, Poland was backed by a guarantee from Britain
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 and France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 which stated that Polish territorial integrity would be defended with their support. On the other hand, British Prime Minister
Prime minister
A prime minister is the most senior minister of cabinet in the executive branch of government in a parliamentary system. In many systems, the prime minister selects and may dismiss other members of the cabinet, and allocates posts to members within the government. In most systems, the prime...

 Neville Chamberlain
Neville Chamberlain
Arthur Neville Chamberlain FRS was a British Conservative politician who served as Prime Minister of the United Kingdom from May 1937 to May 1940. Chamberlain is best known for his appeasement foreign policy, and in particular for his signing of the Munich Agreement in 1938, conceding the...

 and his Foreign Secretary, Lord Halifax, still hoped to strike a deal with Hitler regarding Danzig (and possibly the Polish Corridor), and Hitler hoped for the same. Chamberlain and his supporters believed war could be avoided and hoped Germany would agree to leave the rest of Poland alone. German hegemony over Central Europe was also at stake.

With tensions mounting, Germany turned to aggressive diplomacy as well. On 28 April 1939, it unilaterally withdrew from both the German-Polish Non-Aggression Pact of 1934 and the London Naval Agreement of 1935. Nevertheless, talks over Danzig and the Corridor broke down and months passed without diplomatic interaction between Germany and Poland. During this interim, the Germans learned that France and Britain had failed to secure an alliance with the Soviet Union against Germany and the Soviet Union was interested in an alliance with Germany against Poland. Hitler had already issued orders to prepare for a possible "solution of the Polish problem by military means"—a Case White scenario.
However, with the surprise signing of the Molotov-Ribbentrop Pact
Molotov-Ribbentrop Pact
The Molotov–Ribbentrop Pact, named after the Soviet foreign minister Vyacheslav Molotov and the German foreign minister Joachim von Ribbentrop, was an agreement officially titled the Treaty of Non-Aggression between Germany and the Soviet Union and signed in Moscow in the late hours of 23 August 1939...

 on 23 August, the denouement of secret Nazi-Soviet talks held in Moscow
Moscow
Moscow is the capital, the most populous city, and the most populous federal subject of Russia. The city is a major political, economic, cultural, scientific, religious, financial, educational, and transportation centre of Russia and the continent...

, Germany neutralized the possibility of Soviet opposition to a campaign against Poland and war became imminent. In fact, the Soviets agreed to aid Germany in the event of France or the UK going to war with Germany over Poland and, in a secret protocol of the pact, the Germans and the Soviets agreed to divide Eastern Europe, including Poland, into two spheres of influence; the western ⅓ of the country was to go to Germany and the eastern ⅔ to the Soviet Union.

The German assault was originally scheduled to begin at 04:00 on 26 August. However, on 25 August, the Polish-British Common Defence Pact
Polish-British Common Defence Pact
The Anglo-Polish military alliance refers to agreements reached between the United Kingdom and the Polish Second Republic for mutual assistance in case of military invasion by "a European Power". According to the secret protocol added to the treaty the phrase "a European Power" used in the...

 was signed as an annex to the Franco-Polish Military Alliance
Franco-Polish Military Alliance
The Franco-Polish alliance was the military alliance between Poland and France that was active between 1921 and 1940.-Background:Already during the France-Habsburg rivalry that started in the 16th century, France had tried to find allies to the east of Austria, namely hoping to ally with Poland...

. In this accord, Britain committed itself to the defence of Poland, guaranteeing to preserve Polish independence. At the same time, the British and the Poles were hinting to Berlin that they were willing to resume discussions—not at all how Hitler hoped to frame the conflict. Thus, he wavered and postponed his attack until 1 September, managing to in effect halt the entire invasion "in mid-leap".

However, there was one exception: in the night of 25–6 August, a German sabotage group which had not heard anything about a delay of the invasion made an attack on the Jablunkov Pass
Jablunkov Pass
Jablunkov Pass is a mountain pass in the Beskids, located in the elevation of 553 m above sea level, in the Czech Republic, near the border with Poland and Slovakia....

 and Mosty
Mosty
Mosty may refer to:* Dlouhé Mosty, part of Františkovy Lázně, Czech Republic* Mosty u Českého Těšína, village near Český Těšín, Czech Republic, now part of that town* Mosty u Jablunkova, village in Frýdek-Místek District, Czech Republic...

 railway station in Silesia
Silesia
Silesia is a historical region of Central Europe located mostly in Poland, with smaller parts also in the Czech Republic, and Germany.Silesia is rich in mineral and natural resources, and includes several important industrial areas. Silesia's largest city and historical capital is Wrocław...

. On the morning of 26 August, this group was repelled by Polish troops. The German side described all this as an incident "caused by an insane individual" (see Jabłonków Incident
Jabłonków Incident
Jabłonków Incident refers to the events of the night of August 25/26, 1939, along the Polish - Slovak border. On that night, a group of German Military Intelligence armed agents attacked a rail station in Mosty. The main purpose of the attack was to capture the Jablunkov Pass, with its strategic...

).
On 26 August, Hitler tried to dissuade the British and the French from interfering in the upcoming conflict, even pledging that the Wehrmacht forces would be made available to Britain's empire in the future. The negotiations convinced Hitler that there was little chance the Western Allies would declare war on Germany, and even if they did, because of the lack of "territorial guarantees" to Poland, they would be willing to negotiate a compromise favourable to Germany after its conquest of Poland. Meanwhile, the number of increased overflights by high-altitude reconnaissance aircraft
Reconnaissance aircraft
A reconnaissance aircraft is a manned military aircraft designed, or adapted, to carry out aerial reconnaissance.-History:The majority of World War I aircraft were reconnaissance designs...

 and cross border troop movements signalled that war was imminent.

On 29 August, prompted by the British, Germany issued one last diplomatic offer, with Fall Weiss "Case White" yet to be rescheduled. That evening, the German government responded in a communication that it aimed not only for the restoration of Danzig but also the Polish Corridor
Polish Corridor
The Polish Corridor , also known as Danzig Corridor, Corridor to the Sea or Gdańsk Corridor, was a territory located in the region of Pomerelia , which provided the Second Republic of Poland with access to the Baltic Sea, thus dividing the bulk of Germany from the province of East...

 (which had not previously been part of Hitler’s demands) in addition to the safeguarding of the German minority in Poland. It said that they were willing to commence negotiations, but indicated that a Polish representative with the power to sign an agreement had to arrive in Berlin the next day while in the meantime it would draw up a set of proposals. The British Cabinet was pleased that negotiations had been agreed to but, mindful of how Emil Hacha
Emil Hácha
Emil Hácha was a Czech lawyer, the third President of Czecho-Slovakia from 1938 to 1939. From March 1939, he presided under the German Protectorate of Bohemia and Moravia.-Judicial career:...

 had been forced to sign his country away
German occupation of Czechoslovakia
German occupation of Czechoslovakia began with the Nazi annexation of Czechoslovakia's northern and western border regions, known collectively as the Sudetenland, under terms outlined by the Munich Agreement. Nazi leader Adolf Hitler's pretext for this effort was the alleged privations suffered by...

 under similar circumstances just months earlier, regarded the requirement for an immediate arrival of a Polish representative with full signing powers as an unacceptable ultimatum
Ultimatum
An ultimatum is a demand whose fulfillment is requested in a specified period of time and which is backed up by a threat to be followed through in case of noncompliance. An ultimatum is generally the final demand in a series of requests...

. On the night of 30/31 August, German Foreign Minister Joachim von Ribbentrop
Joachim von Ribbentrop
Ulrich Friedrich Wilhelm Joachim von Ribbentrop was Foreign Minister of Germany from 1938 until 1945. He was later hanged for war crimes after the Nuremberg Trials.-Early life:...

 read a 16-point German proposal to the British ambassador. When the ambassador requested a copy of the proposals for transmission to the Polish government Ribbentrop refused on the grounds that the requested Polish representative had failed to arrive by midnight. When Polish Ambassador Lipski went to see Ribbentrop later on 31 August to indicate that Poland was favorably disposed to negotiations, he announced that he did not have the full power to sign, and Ribbentrop dismissed him. It was then broadcast that Poland had rejected Germany's offer, and negotiations with Poland came to an end. Hitler issued orders for the invasion to commence soon afterwards.

On 29 August, German saboteurs planted a bomb at the railway station in Tarnów
Tarnów rail station bomb attack
The Tarnów rail station bomb attack was a bombing carried out by a German agent at Tarnów, Poland. It occurred in the night of August 28, 1939, when a time bomb planted by the agent exploded, killing 20 people and wounding 35....

 and killed 21 passengers, leaving 35 wounded.

On 30 August, the Polish Navy
Polish Navy
The Marynarka Wojenna Rzeczypospolitej Polskiej - MW RP Polish Navy, is the branch of Republic of Poland Armed Forces responsible for naval operations...

 sent its destroyer flotilla
Flotilla
A flotilla , or naval flotilla, is a formation of small warships that may be part of a larger fleet. A flotilla is usually composed of a homogeneous group of the same class of warship, such as frigates, destroyers, torpedo boats, submarines, gunboats, or minesweepers...

 to Britain, executing Operation Peking. On the same day, Marshal of Poland
Marshal of Poland
Marshal of Poland is the highest rank in the Polish Army. It has been granted to only six officers. At present, this rank is equivalent to a Field Marshal or General of the Army in other NATO armies.-History:...

 Edward Rydz-Śmigły announced the mobilization
Mobilization
Mobilization is the act of assembling and making both troops and supplies ready for war. The word mobilization was first used, in a military context, in order to describe the preparation of the Prussian army during the 1850s and 1860s. Mobilization theories and techniques have continuously changed...

 of Polish troops. However, he was pressured into revoking the order by the French, who apparently still hoped for a diplomatic settlement, failing to realize that the Germans were fully mobilized and concentrated at the Polish border. During the night of 31 August, the Gleiwitz incident
Gleiwitz incident
The Gleiwitz incident was a staged attack by Nazi forces posing as Poles on 31 August 1939, against the German radio station Sender Gleiwitz in Gleiwitz, Upper Silesia, Germany on the eve of World War II in Europe....

, a false flag
False flag
False flag operations are covert operations designed to deceive the public in such a way that the operations appear as though they are being carried out by other entities. The name is derived from the military concept of flying false colors; that is flying the flag of a country other than one's own...

 attack on the radio station, was staged near the border city of Gleiwitz
Gliwice
Gliwice is a city in Upper Silesia in southern Poland, near Katowice. Gliwice is the west district of the Upper Silesian Metropolitan Union – a metropolis with a population of 2 million...

 by German units posing as Polish troops, in Upper Silesia
Upper Silesia
Upper Silesia is the southeastern part of the historical and geographical region of Silesia. Since the 9th century, Upper Silesia has been part of Greater Moravia, the Duchy of Bohemia, the Piast Kingdom of Poland, again of the Lands of the Bohemian Crown and the Holy Roman Empire, as well as of...

 as part of the wider Operation Himmler
Operation Himmler
Operation Himmler was a Nazi Germany false flag project to create the appearance of Polish aggression against Germany, which was subsequently used by Nazi propaganda to justify the invasion of Poland...

. On 31 August 1939, Hitler ordered hostilities against Poland to start at 4:45 the next morning. Because of the prior stoppage, Poland managed to mobilize only 70% of its planned forces, and many units were still forming or moving to their designated frontline positions.

Opposing forces

Germany

Germany had a substantial numerical advantage over Poland and had developed a significant military prior to the conflict. The Heer
German Army
The German Army is the land component of the armed forces of the Federal Republic of Germany. Following the disbanding of the Wehrmacht after World War II, it was re-established in 1955 as the Bundesheer, part of the newly formed West German Bundeswehr along with the Navy and the Air Force...

(army) had some 2,400 tank
Tank
A tank is a tracked, armoured fighting vehicle designed for front-line combat which combines operational mobility, tactical offensive, and defensive capabilities...

s organized into six panzer
Panzer
A Panzer is a German language word that, when used as a noun, means "tank". When it is used as an adjective, it means either tank or "armoured" .- Etymology :...

divisions, utilizing a new operational doctrine. It held that these divisions should act in coordination with other elements of the military, punching holes in the enemy line and isolating selected units, which would be encircled
Encirclement
Encirclement is a military term for the situation when a force or target is isolated and surrounded by enemy forces. The German term for this is Kesselschlacht ; a comparable English term might be "in the bag"....

 and destroyed. This would be followed up by less-mobile mechanized infantry and foot soldiers. The Luftwaffe
Luftwaffe
Luftwaffe is a generic German term for an air force. It is also the official name for two of the four historic German air forces, the Wehrmacht air arm founded in 1935 and disbanded in 1946; and the current Bundeswehr air arm founded in 1956....

(air force) provided both tactical and strategic air power, particularly dive bomber
Dive bomber
A dive bomber is a bomber aircraft that dives directly at its targets in order to provide greater accuracy for the bomb it drops. Diving towards the target reduces the distance the bomb has to fall, which is the primary factor in determining the accuracy of the drop...

s that disrupted lines of supply and communications. Together, the so-called "new" methods, were nicknamed "Blitzkrieg
Blitzkrieg
For other uses of the word, see: Blitzkrieg Blitzkrieg is an anglicized word describing all-motorised force concentration of tanks, infantry, artillery, combat engineers and air power, concentrating overwhelming force at high speed to break through enemy lines, and, once the lines are broken,...

" (lightning war). Historian Basil Liddell Hart
Basil Liddell Hart
Sir Basil Henry Liddell Hart , usually known before his knighthood as Captain B. H. Liddell Hart, was an English soldier, military historian and leading inter-war theorist.-Life and career:...

 claimed "Poland was a full demonstration of the Blitzkrieg theory." Some other historians, however, disagree.

Aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

 played a major role in the campaign. Bombers also attacked cities, causing huge losses amongst the civilian population through terror bombing. The Luftwaffe forces consisted of 1,180 fighter
Fighter aircraft
A fighter aircraft is a military aircraft designed primarily for air-to-air combat with other aircraft, as opposed to a bomber, which is designed primarily to attack ground targets...

s, 290 Ju 87 Stuka
Junkers Ju 87
The Junkers Ju 87 or Stuka was a two-man German ground-attack aircraft...

 dive bomber
Dive bomber
A dive bomber is a bomber aircraft that dives directly at its targets in order to provide greater accuracy for the bomb it drops. Diving towards the target reduces the distance the bomb has to fall, which is the primary factor in determining the accuracy of the drop...

s, 1,100 conventional bombers (mainly Heinkel He 111
Heinkel He 111
The Heinkel He 111 was a German aircraft designed by Siegfried and Walter Günter in the early 1930s in violation of the Treaty of Versailles. Often described as a "Wolf in sheep's clothing", it masqueraded as a transport aircraft, but its purpose was to provide the Luftwaffe with a fast medium...

s and Dornier Do 17
Dornier Do 17
The Dornier Do 17, sometimes referred to as the Fliegender Bleistift , was a World War II German light bomber produced by Claudius Dornier's company, Dornier Flugzeugwerke...

s), and an assortment of 550 transport and 350 reconnaissance aircraft. In total, Germany had close to 4,000 aircraft, most of them modern. A force of 2,315 aircraft was assigned to Weiss. Due to its prior participation in the Spanish Civil War
Spanish Civil War
The Spanish Civil WarAlso known as The Crusade among Nationalists, the Fourth Carlist War among Carlists, and The Rebellion or Uprising among Republicans. was a major conflict fought in Spain from 17 July 1936 to 1 April 1939...

, the Luftwaffe was probably the most experienced, best trained and best equipped air force in the world in 1939.

Poland

Between 1936 and 1939, Poland invested heavily in the Central Industrial Region. Preparations for a defensive war with Germany were ongoing for many years, but most plans assumed fighting would not begin before 1942. To raise funds for industrial development, Poland sold much of the modern equipment it produced. In 1936, a National Defence Fund
Fundusz Obrony Narodowej
Fundusz Obrony Narodowej was an attempt by both the government of the Second Polish Republic and the Polish nation to collect funds necessary for improving fighting ability of the Polish Army before the increasingly likely World War II....

 was set up to collect funds necessary for strengthening the Polish Armed forces. The Polish Army had approximately a million soldiers, but less than ½ of them were mobilized by 1 September. Latecomers sustained significant casualties when public transport became targets of the Luftwaffe. The Polish military had fewer armored forces than the Germans, and these units, dispersed within the infantry, were unable to effectively engage the enemy.

Experiences in the Polish-Soviet War
Polish-Soviet War
The Polish–Soviet War was an armed conflict between Soviet Russia and Soviet Ukraine and the Second Polish Republic and the Ukrainian People's Republic—four states in post–World War I Europe...

 shaped Polish Army organizational and operational doctrine. Unlike the trench warfare
Trench warfare
Trench warfare is a form of occupied fighting lines, consisting largely of trenches, in which troops are largely immune to the enemy's small arms fire and are substantially sheltered from artillery...

 of World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

, the Polish-Soviet War was a conflict in which the cavalry
Cavalry
Cavalry or horsemen were soldiers or warriors who fought mounted on horseback. Cavalry were historically the third oldest and the most mobile of the combat arms...

's mobility played a decisive role. Poland acknowledged the benefits of mobility but was unable to invest heavily in many of the expensive, unproven inventions since then. In spite of this, Polish cavalry
Polish cavalry
The Polish cavalry can trace its origins back to the days of Medieval mounted knights. Poland had always been a country of flatlands and fields and mounted forces operate well in this environment...

 brigade
Brigade
A brigade is a major tactical military formation that is typically composed of two to five battalions, plus supporting elements depending on the era and nationality of a given army and could be perceived as an enlarged/reinforced regiment...

s were used as a mobile mounted infantry
Mounted infantry
Mounted infantry were soldiers who rode horses instead of marching, but actually fought on foot . The original dragoons were essentially mounted infantry...

 and had some successes against both German infantry and cavalry.
The Polish Air Force
Polish Air Force
The Polish Air Force is the military Air Force wing of the Polish Armed Forces. Until July 2004 it was officially known as Wojska Lotnicze i Obrony Powietrznej...

 (Lotnictwo Wojskowe) was at a severe disadvantage against the German Luftwaffe, although it was not destroyed on the ground early on, as is commonly believed. The Polish Air Force lacked modern fighters, but its pilots were among the world's best trained, as proven a year later in the Battle of Britain
Battle of Britain
The Battle of Britain is the name given to the World War II air campaign waged by the German Air Force against the United Kingdom during the summer and autumn of 1940...

, in which the Poles played a major part.

Overall, the Germans enjoyed numerical and qualitative aircraft superiority. Poland had only about 600 aircraft, of which only 37 P-37 Łoś bombers were modern and comparable to its German counterparts. The Polish Air Force had roughly 185 PZL P.11
PZL P.11
The PZL P.11 was a Polish fighter aircraft, designed in the early 1930s by PZL in Warsaw. It was briefly considered to be the most advanced fighter aircraft design in the world...

 and some 95 PZL P.7
PZL P.7
-References:NotesBibliography* Cynk, Jerzy B. History of the Polish Air Force 1918-1968. Reading, Berkshire, UK: Osprey Publishing Ltd., 1972.* Cynk, Jerzy B. Polish Aircraft, 1893-1939. London: Putnam & Company Ltd., 1971. ISBN 0-370-00085-4....

 fighters, 175 PZL.23 Karaś
PZL.23 Karas
|-Specifications :-See also:-References:NotesBibliography* Angelucci, Enzo and Paolo Matricardi. World War II Airplanes . Chicago: Rand McNally, 1978. ISBN 0-52888-170-1....

 Bs, 35 Karaś As, and by September, over 100 PZL.37s were produced. However, for the September Campaign, only some 70% of those aircraft were mobilized. Only 36 PZL.37s were deployed. All those aircraft were of indigenous Polish design, with the bombers being more modern than fighters, according to the Ludomił Rayski air force expansion plan, which relied on a strong bomber force. The Polish fighters were a generation older than their German counterparts; the PZL P.11 fighter—produced in the early 1930s—had a top speed of only 365 km/h (226.8 mph), far less than German bombers. To compensate, the pilots relied on its maneuverability and high diving speed.
The tank force consisted of two armored brigades, four independent tank battalions and some 30 companies of TKS
TKS
The TK and TKS were Polish tankettes during the Second World War.-Design and development:The TK tankette was a Polish design produced from 1931 that was based upon an improved chassis of the British Carden Loyd tankette. The TKS was an improved model with a new hull and a more powerful engine...

 tankettes attached to infantry divisions and cavalry brigades.
A standard tank of the Polish Army during the Polish Defensive War of 1939 was the 7TP light tank
7TP
The 7TP was the Polish light tank of the Second World War. A development of the British Vickers 6-ton, it was significantly better armed than its most common opponents, the German Panzer I and Panzer II. A standard tank of the Polish Army during the Polish Defensive War of 1939, its production...

. It was the first tank in the world to be equipped with a diesel engine and 360° Gundlach periscope
Vickers Tank Periscope MK.IV
The Vickers Tank Periscope MK.IV, invented by Polish engineer Rudolf Gundlach, was first patented in 1936 as Gundlach Peryskop obrotowy. It was the first device to allow the tank commander to have a 360-degree view from his turret, with a single periscope...

. The 7TP was significantly better armed than its most common opponents, the German Panzer I
Panzer I
The Panzer I was a light tank produced in Germany in the 1930s. The name is short for the German ' , abbreviated . The tank's official German ordnance inventory designation was SdKfz 101 .Design of the Panzer I began in 1932 and mass production in 1934...

 and II
Panzer II
The Panzer II was the common name for a family of German tanks used in World War II. The official German designation was Panzerkampfwagen II...

, but only 140 tanks were produced between 1935 and the outbreak of the war. Poland had also a few relatively modern imported designs, such as 50 Renault R35 tanks and 38 Vickers E tanks.

The Polish Navy
Polish Navy
The Marynarka Wojenna Rzeczypospolitej Polskiej - MW RP Polish Navy, is the branch of Republic of Poland Armed Forces responsible for naval operations...

 was a small fleet of destroyer
Destroyer
In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from...

s, submarine
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

s and smaller support vessels. Most Polish surface units followed Operation Peking
Peking Plan
The Peking PlanThe "Peking" in the name is the traditional English spelling of the former name of the city that is now the capital of China, which is now spelled in the pinyin system 'Beijing'. At the time, the city was not the capital, and its name was Peiping. Before the Second World War in the...

, leaving Polish ports on 20 August and escaping by way of the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...

 to join with the British Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

. Submarine forces participated in Operation Worek, with the goal of engaging and damaging German shipping in the Baltic Sea
Baltic Sea
The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...

, but they had much less success. In addition, many merchant marine
Ship transport
Ship transport is watercraft carrying people or goods . Sea transport has been the largest carrier of freight throughout recorded history. Although the importance of sea travel for passengers has decreased due to aviation, it is effective for short trips and pleasure cruises...

 ships joined the British merchant fleet and took part in wartime convoy
Convoy
A convoy is a group of vehicles, typically motor vehicles or ships, traveling together for mutual support and protection. Often, a convoy is organized with armed defensive support, though it may also be used in a non-military sense, for example when driving through remote areas.-Age of Sail:Naval...

s.

German plan

The German plan for what became known as the September Campaign was devised by General Franz Halder
Franz Halder
Franz Halder was a German General and the head of the Army General Staff from 1938 until September, 1942, when he was dismissed after frequent disagreements with Adolf Hitler.-Early life:...

, chief of the general staff, and directed by General Walther von Brauchitsch
Walther von Brauchitsch
Heinrich Alfred Hermann Walther von Brauchitsch was a German field marshal and the Oberbefehlshaber des Heeres in the early years of World War II.-Biography:...

, the commander in chief of the upcoming campaign. It called for the start of hostilities before a declaration of war
Declaration of war
A declaration of war is a formal act by which one nation goes to war against another. The declaration is a performative speech act by an authorized party of a national government in order to create a state of war between two or more states.The legality of who is competent to declare war varies...

, and pursued a doctrine of mass encirclement and destruction of enemy forces. The infantry—far from completely mechanized but fitted with fast moving artillery and logistic support—was to be supported by Panzers and small numbers of truck-mounted infantry (the Schützen regiments, forerunners of the panzergrenadier
Panzergrenadier
is a German term for motorised or mechanized infantry, as introduced during World War II. It is used in the armies of Austria, Chile, Germany and Switzerland.-Forerunners:...

s
) to assist the rapid movement of troops and concentrate on localized parts of the enemy front, eventually isolating segments of the enemy, surrounding, and destroying them. The pre-war "armored idea" (which an American journalist in 1939 dubbed Blitzkrieg
Blitzkrieg
For other uses of the word, see: Blitzkrieg Blitzkrieg is an anglicized word describing all-motorised force concentration of tanks, infantry, artillery, combat engineers and air power, concentrating overwhelming force at high speed to break through enemy lines, and, once the lines are broken,...

)—which was advocated by some generals, including Heinz Guderian
Heinz Guderian
Heinz Wilhelm Guderian was a German general during World War II. He was a pioneer in the development of armored warfare, and was the leading proponent of tanks and mechanization in the Wehrmacht . Germany's panzer forces were raised and organized under his direction as Chief of Mobile Forces...

—would have had the armor punching holes in the enemy's front and ranging deep into rear areas; in actuality, the campaign in Poland would be fought along more traditional lines. This stemmed from conservatism on the part of the German high command, who mainly restricted the role of armor and mechanized forces to supporting the conventional infantry divisions.

Poland's terrain was well suited for mobile operations when the weather cooperated; the country had flat plain
Plain
In geography, a plain is land with relatively low relief, that is flat or gently rolling. Prairies and steppes are types of plains, and the archetype for a plain is often thought of as a grassland, but plains in their natural state may also be covered in shrublands, woodland and forest, or...

s with long frontiers totalling almost 5600 km (3,479.7 mi), Poland's long border with Germany on the west and north—facing East Prussia
East Prussia
East Prussia is the main part of the region of Prussia along the southeastern Baltic Coast from the 13th century to the end of World War II in May 1945. From 1772–1829 and 1878–1945, the Province of East Prussia was part of the German state of Prussia. The capital city was Königsberg.East Prussia...

—extended 2000 km (1,242.7 mi). Those had been lengthened by another 300 km (186.4 mi) on the southern side in the aftermath of the Munich Agreement of 1938. The German incorporation of Bohemia and Moravia and creation of the German puppet state
Puppet state
A puppet state is a nominal sovereign of a state who is de facto controlled by a foreign power. The term refers to a government controlled by the government of another country like a puppeteer controls the strings of a marionette...

 of Slovakia meant that Poland's southern flank was exposed.

German planners intended to fully exploit their long border with the great enveloping manoeuver of Fall Weiss. German units were to invade Poland from three directions:
  • A main attack over the western Polish border. This was to be carried out by Army Group South commanded by General Gerd von Rundstedt
    Gerd von Rundstedt
    Karl Rudolf Gerd von Rundstedt was a Generalfeldmarschall of the German Army during World War II. He held some of the highest field commands in all phases of the war....

    , attacking from German Silesia
    Silesia
    Silesia is a historical region of Central Europe located mostly in Poland, with smaller parts also in the Czech Republic, and Germany.Silesia is rich in mineral and natural resources, and includes several important industrial areas. Silesia's largest city and historical capital is Wrocław...

     and from the Moravia
    Moravia
    Moravia is a historical region in Central Europe in the east of the Czech Republic, and one of the former Czech lands, together with Bohemia and Silesia. It takes its name from the Morava River which rises in the northwest of the region...

    n and Slovak border: General Johannes Blaskowitz
    Johannes Blaskowitz
    Johannes Albrecht Blaskowitz was a German general during World War II. He was also a recipient of the Knight's Cross of the Iron Cross with Oak Leaves and Swords...

    's 8th Army was to drive eastward against Łódź; General Wilhelm List's 14th Army was to push on toward Kraków
    Kraków
    Kraków also Krakow, or Cracow , is the second largest and one of the oldest cities in Poland. Situated on the Vistula River in the Lesser Poland region, the city dates back to the 7th century. Kraków has traditionally been one of the leading centres of Polish academic, cultural, and artistic life...

     and to turn the Poles' Carpathian
    Carpathian Mountains
    The Carpathian Mountains or Carpathians are a range of mountains forming an arc roughly long across Central and Eastern Europe, making them the second-longest mountain range in Europe...

     flank; and General Walter von Reichenau's 10th Army, in the centre with Army Group South's armor, was to deliver the decisive blow with a northeastward thrust into the heart of Poland.
  • A second route of attack from northern Prussia
    Prussia
    Prussia was a German kingdom and historic state originating out of the Duchy of Prussia and the Margraviate of Brandenburg. For centuries, the House of Hohenzollern ruled Prussia, successfully expanding its size by way of an unusually well-organized and effective army. Prussia shaped the history...

    . General Fedor von Bock
    Fedor von Bock
    Fedor von Bock was a German Generalfeldmarshall who served in the Wehrmacht during the Second World War. As a leader who lectured his soldiers about the honor of dying for the German Fatherland, he was nicknamed "Der Sterber"...

     commanded Army Group North, comprising General Georg von Küchler
    Georg von Küchler
    Georg Karl Friedrich Wilhelm von Küchler was a German Field Marshal during the Second World War. He was also a recipient of the Knight's Cross of the Iron Cross with Oak Leaves...

    's 3rd Army, which was to strike southward from East Prussia, and General Günther von Kluge
    Günther von Kluge
    Günther Adolf Ferdinand “Hans” von Kluge was a German military leader. He was born in Posen into a Prussian military family. Kluge rose to the rank of Field Marshal in the Wehrmacht. He was also a recipient of the Knight's Cross of the Iron Cross with Oak Leaves and Swords...

    's 4th Army, which was to attack eastward across the base of the Polish Corridor
    Polish Corridor
    The Polish Corridor , also known as Danzig Corridor, Corridor to the Sea or Gdańsk Corridor, was a territory located in the region of Pomerelia , which provided the Second Republic of Poland with access to the Baltic Sea, thus dividing the bulk of Germany from the province of East...

    .
  • A tertiary attack by part of Army Group South's allied Slovak units from Slovakia.
  • From within Poland, the German minority would assist by engaging in diversion and sabotage operations through Selbstschutz
    Selbstschutz
    Selbstschutz stands for two organisations:# A name used by a number of paramilitary organisations created by ethnic Germans in Central and Eastern Europe# A name for self-defence measures and units in ethnic German, Austrian, and Swiss civil defence....

    units prepared before the war.


All three assaults were to converge on Warsaw
Warsaw
Warsaw is the capital and largest city of Poland. It is located on the Vistula River, roughly from the Baltic Sea and from the Carpathian Mountains. Its population in 2010 was estimated at 1,716,855 residents with a greater metropolitan area of 2,631,902 residents, making Warsaw the 10th most...

, while the main Polish army was to be encircled
Encirclement
Encirclement is a military term for the situation when a force or target is isolated and surrounded by enemy forces. The German term for this is Kesselschlacht ; a comparable English term might be "in the bag"....

 and destroyed west of the Vistula
Vistula
The Vistula is the longest and the most important river in Poland, at 1,047 km in length. The watershed area of the Vistula is , of which lies within Poland ....

. Fall Weiss was initiated on 1 September 1939, and was the first operation of World War II in Europe.

Polish defence plan

The Polish political determination to deploy forces directly at the German-Polish border, based on the British Government's promise to come to Poland's aid in the event of invasion, shaped the country's defence plan, "Plan West
Plan West
Plan Zachód was a military plan of the Polish Army of the Second Polish Republic, for defence against invasion from Nazi Germany. It was designed in the late 1930s.-Background:...

". Poland's most valuable natural resources, industry and population were located along the western border in Eastern Upper Silesia. Polish policy centred on their protection especially since many politicians feared that if Poland were to retreat from the regions disputed by Germany, Britain and France would sign a separate peace treaty with Germany similar to the Munich Agreement
Munich Agreement
The Munich Pact was an agreement permitting the Nazi German annexation of Czechoslovakia's Sudetenland. The Sudetenland were areas along Czech borders, mainly inhabited by ethnic Germans. The agreement was negotiated at a conference held in Munich, Germany, among the major powers of Europe without...

 of 1938. The fact that none of Poland's allies had specifically guaranteed Polish borders or territorial integrity
Territorial integrity
Territorial integrity is the principle under international law that nation-states should not attempt to promote secessionist movements or to promote border changes in other nation-states...

 certainly did not help in easing Polish concerns. For these reasons, Poland disregarded French advice to deploy the bulk of their forces behind the natural barriers such as the Vistula
Vistula
The Vistula is the longest and the most important river in Poland, at 1,047 km in length. The watershed area of the Vistula is , of which lies within Poland ....

 and San rivers, even though some Polish generals supported it as a better strategy. The West Plan did permit the Polish armies to retreat inside the country, but it was supposed to be a slow retreat behind prepared positions and was intended to give the armed forces time to complete its mobilization and execute a general counteroffensive with the support of the Western Allies
Allies of World War II
The Allies of World War II were the countries that opposed the Axis powers during the Second World War . Former Axis states contributing to the Allied victory are not considered Allied states...

.
The Polish General Staff had not begun elaborating the "West" defence plan until March 4, 1939. It was assumed that the Polish Army, fighting in the initial phase of the war alone, would be compelled to defend the western regions of the country. The plan of operations took into account, first of all, the numerical and material superiority of the enemy and, consequently, assumed the defensive character of Polish operations. The Polish intentions were: the defence of the western regions judged as indispensable for waging the war, the taking advantage of the propicious conditions for counterblows by reserve units, the avoidance of being smashed before the beginning of Allied operations in the West and the making of decisions depending of the existing situation. The operational plan
Operational plan
Operational plan is a term that can be used for* Military purposes, see Operation plan or "OPLAN"* Business purposes, see Business operations* Operational planning, see operational planning...

 had not been elaborated in detail and concerned only the first stage of operations.

The British and French estimated that Poland should be able to defend itself for two to three months, while Poland estimated it could do so for at least six months. Poland drafted its estimates based upon the expectation that the Western Allies honor their treaty obligations and quickly start an offensive of their own. In addition, the French and British expected the war to develop into trench warfare
Trench warfare
Trench warfare is a form of occupied fighting lines, consisting largely of trenches, in which troops are largely immune to the enemy's small arms fire and are substantially sheltered from artillery...

 much like World War I. The Polish government was not notified of this strategy and based all of its defence plans on promises of quick relief by their Western allies.

Polish forces were stretched thinly along the Polish-German border and lacked compact defence lines and good defence positions along disadvantageous terrain. This strategy also left supply lines poorly protected. One-third of Poland's forces were massed in or near the Polish Corridor
Polish Corridor
The Polish Corridor , also known as Danzig Corridor, Corridor to the Sea or Gdańsk Corridor, was a territory located in the region of Pomerelia , which provided the Second Republic of Poland with access to the Baltic Sea, thus dividing the bulk of Germany from the province of East...

, making them vulnerable to a double envelopment
Pincer movement
The pincer movement or double envelopment is a military maneuver. The flanks of the opponent are attacked simultaneously in a pinching motion after the opponent has advanced towards the center of an army which is responding by moving its outside forces to the enemy's flanks, in order to surround it...

 from East Prussia and the west. Another third were concentrated in the north-central part of the country, between the major cities of Łódź and Warsaw. The forward positioning of Polish forces vastly increased the difficulty of carrying out strategic maneuvers, compounded by inadequate mobility, as Polish units often lacked the ability to retreat from their defensive positions as they were being overrun by more mobile German mechanized formations.
As the prospect of conflict increased, the British government pressed Marshal Edward Rydz-Śmigły, to evacuate the most modern elements of the Polish Navy
Polish Navy
The Marynarka Wojenna Rzeczypospolitej Polskiej - MW RP Polish Navy, is the branch of Republic of Poland Armed Forces responsible for naval operations...

 from the Baltic Sea. In the event of war the Polish military leaders realized that the ships which remained in the Baltic were likely to be quickly sunk by the Germans. Furthermore, the Danish straits
Danish straits
The Danish straits are the three channels connecting the Baltic Sea to the North Sea through the Kattegat and Skagerrak. They transect Denmark, and are not to be confused with the Denmark Strait between Greenland and Iceland...

 were well within operating range of the German Kriegsmarine
Kriegsmarine
The Kriegsmarine was the name of the German Navy during the Nazi regime . It superseded the Kaiserliche Marine of World War I and the post-war Reichsmarine. The Kriegsmarine was one of three official branches of the Wehrmacht, the unified armed forces of Nazi Germany.The Kriegsmarine grew rapidly...

and Luftwaffe, so there was little chance of an evacuation plan succeeding if implemented after hostilities began. Four days after the signing of the Polish-British Common Defence Pact
Polish-British Common Defence Pact
The Anglo-Polish military alliance refers to agreements reached between the United Kingdom and the Polish Second Republic for mutual assistance in case of military invasion by "a European Power". According to the secret protocol added to the treaty the phrase "a European Power" used in the...

, three destroyers of the Polish Navy executed the Peking Plan
Peking Plan
The Peking PlanThe "Peking" in the name is the traditional English spelling of the former name of the city that is now the capital of China, which is now spelled in the pinyin system 'Beijing'. At the time, the city was not the capital, and its name was Peiping. Before the Second World War in the...

 and consequently evacuated to Great Britain.

Although the Polish military had prepared for conflict, the civilian population remained largely unprepared. Polish pre-war propaganda
Propaganda
Propaganda is a form of communication that is aimed at influencing the attitude of a community toward some cause or position so as to benefit oneself or one's group....

 emphasized that any German invasion would be easily repelled. Consequently, Polish defeats during the German invasion came as a shock to the civilian population, who were largely unprepared. Lacking training for such a disaster, the civilian population panicked and retreated east, spreading chaos, lowering troop morale and making road transportation for Polish troops very difficult.

Phase 1: German invasion

Following several German-staged incidents (like the Gleiwitz incident
Gleiwitz incident
The Gleiwitz incident was a staged attack by Nazi forces posing as Poles on 31 August 1939, against the German radio station Sender Gleiwitz in Gleiwitz, Upper Silesia, Germany on the eve of World War II in Europe....

, a part of Operation Himmler
Operation Himmler
Operation Himmler was a Nazi Germany false flag project to create the appearance of Polish aggression against Germany, which was subsequently used by Nazi propaganda to justify the invasion of Poland...

), which German propaganda used as an excuse to claim that German forces were acting in self-defence
Self-defense
Self-defense, self-defence or private defense is a countermeasure that involves defending oneself, one's property or the well-being of another from physical harm. The use of the right of self-defense as a legal justification for the use of force in times of danger is available in many...

, the first regular act of war took place on 1 September 1939, at 04:40, when the Luftwaffe attacked the Polish town of Wieluń
Bombing of Wielun
The bombing of Wieluń refers to the bombing of the Polish town of Wieluń by the German Luftwaffe on 1 September 1939. The Luftwaffe started bombing Wielun at 4:40 am, five minutes before the shelling of Westerplatte, which has traditionally been considered the beginning of World War II. It is...

, destroying 75% of the city and killing close to 1,200 people, most of them civilians. This invasion subsequently began World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. Five minutes later, the old German pre-dreadnought battleship Schleswig-Holstein
German battleship Schleswig-Holstein
SMS Schleswig-Holstein, one of the five s, was the last pre-dreadnought battleship built by the German Kaiserliche Marine. The ship was laid down in the Germaniawerft dockyard in Kiel in August 1905 and commissioned into the fleet nearly three years later in July 1908...

 opened fire on the Polish military transit depot at Westerplatte
Battle of Westerplatte
The Battle of Westerplatte was the very first battle that took place after Germany invaded Poland and World War II began in Europe. During the first week of September 1939, a Military Transit Depot on the peninsula of Westerplatte, manned by fewer than 200 Polish soldiers, held out for seven days...

 in the Free City of Danzig
Free City of Danzig
The Free City of Danzig was a semi-autonomous city-state that existed between 1920 and 1939, consisting of the Baltic Sea port of Danzig and surrounding areas....

 on the Baltic Sea
Baltic Sea
The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...

. At 08:00, German troops—still without a formal declaration of war issued—attacked near the Polish town of Mokra
Battle of Mokra
The Battle of Mokra took place on September 1, 1939 near the village of Mokra, 5 km north from Kłobuck, 23 km north-west from Częstochowa, Poland...

. The Battle of the Border
Battle of the Border
The Battle of the Border refers to the battles that occurred in the first days of the Nazi Germany invasion of Poland in September, 1939...

 had begun. Later that day, the Germans attacked on Poland's Bestern, southern and northern borders, while German aircraft began raids on Polish cities. The main axis of attack led eastwards from Germany proper through the western Polish border. Supporting attacks came from East Prussia
East Prussia
East Prussia is the main part of the region of Prussia along the southeastern Baltic Coast from the 13th century to the end of World War II in May 1945. From 1772–1829 and 1878–1945, the Province of East Prussia was part of the German state of Prussia. The capital city was Königsberg.East Prussia...

 in the north, and a co-operative German-Slovak tertiary attack by units (Field Army "Bernolák"
Field Army Bernolák
The Field Army Bernolák was an infantry unit during World War II. In Jozef Tiso's Axis WWII Slovak Republic, it took part in the German invasion of Poland in 1939 and the invasion of the Soviet Union in 1941....

) from German-allied Slovakia in the south. All three assaults converged on the Polish capital of Warsaw.
The Allied governments declared war on Germany on 3 September; however, they failed to provide any meaningful support
Western betrayal
Western betrayal, also called Yalta betrayal, refers to a range of critical views concerning the foreign policies of several Western countries between approximately 1919 and 1968 regarding Eastern Europe and Central Europe...

. The German-French border saw only a few minor skirmishes
Saar Offensive
The Saar Offensive was a French operation into Saarland on the German 1st Army defence sector in the early stages of World War II. The purpose of the attack was to assist Poland, which was then under attack...

, although the majority of German forces, including 85% of their armoured forces, were engaged in Poland. Despite some Polish successes in minor border battles, German technical, operational and numerical superiority forced the Polish armies to retreat from the borders towards Warsaw and Lwów. The Luftwaffe gained air superiority early in the campaign. By destroying communications, the Luftwaffe increased the pace of the advance which overran Polish airstrips and early warning sites, causing logistical problems for the Poles. Many Polish Air Force
Polish Air Force
The Polish Air Force is the military Air Force wing of the Polish Armed Forces. Until July 2004 it was officially known as Wojska Lotnicze i Obrony Powietrznej...

 units ran low on supplies, 98 of their number withdrew into then-neutral Romania
Romania
Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...

. The Polish initial strength of 400 was reduced to just 54 by 14 September and air opposition virtually ceased.

By 3 September, when Günther von Kluge
Günther von Kluge
Günther Adolf Ferdinand “Hans” von Kluge was a German military leader. He was born in Posen into a Prussian military family. Kluge rose to the rank of Field Marshal in the Wehrmacht. He was also a recipient of the Knight's Cross of the Iron Cross with Oak Leaves and Swords...

 in the north had reached the Vistula river (some 10 km (6.2 mi) from the German border at that time) and Georg von Küchler
Georg von Küchler
Georg Karl Friedrich Wilhelm von Küchler was a German Field Marshal during the Second World War. He was also a recipient of the Knight's Cross of the Iron Cross with Oak Leaves...

 was approaching the Narew
Narew
The Narew River , in western Belarus and north-eastern Poland, is a left tributary of the Vistula river...

 River, Walther von Reichenau
Walther von Reichenau
Walter von Reichenau was a German Generalfeldmarschall during World War II.-History:Reichenau was born in Karlsruhe to a Prussian general and joined the German Army in 1903. During World War I he served on the Western Front...

's armor was already beyond the Warta river; two days later, his left wing was well to the rear of Łódź and his right wing at the town of Kielce
Kielce
Kielce ) is a city in central Poland with 204,891 inhabitants . It is also the capital city of the Świętokrzyskie Voivodeship since 1999, previously in Kielce Voivodeship...

. By 8 September, one of his armored corps—having advanced 225 km (139.8 mi) in the first week of the campaign—reached the outskirts of Warsaw. Light divisions on Reichenau's right were on the Vistula
Vistula
The Vistula is the longest and the most important river in Poland, at 1,047 km in length. The watershed area of the Vistula is , of which lies within Poland ....

 between Warsaw and the town of Sandomierz
Sandomierz
Sandomierz is a city in south-eastern Poland with 25,714 inhabitants . Situated in the Świętokrzyskie Voivodeship , previously in Tarnobrzeg Voivodeship . It is the capital of Sandomierz County . Sandomierz is known for its Old Town, a major tourist attraction...

 by 9 September while List—in the south—was on the San River
San River
The San is a river in southeastern Poland and western Ukraine, a tributary of the Vistula River, with a length of 433 km and a basin area of 16,861 km2...

 above and below the town of Przemyśl
Przemysl
Przemyśl is a city in south-eastern Poland with 66,756 inhabitants, as of June 2009. In 1999, it became part of the Podkarpackie Voivodeship; it was previously the capital of Przemyśl Voivodeship....

. At the same time, Guderian led his 3rd Army tanks across the Narew, attacking the line of the Bug River
Bug River
The Bug River is a left tributary of the Narew river flows from central Ukraine to the west, passing along the Ukraine-Polish and Polish-Belarusian border and into Poland, where it empties into the Narew river near Serock. The part between the lake and the Vistula River is sometimes referred to as...

, already encircling Warsaw. All the German armies made progress in fulfilling their parts of the Fall Weiss plan. The Polish armies were splitting up into uncoordinated fragments, some of which were retreating while others were launching disjointed attacks on the nearest German columns.
Polish forces abandoned the regions of Pomerelia
Pomerelia
Pomerelia is a historical region in northern Poland. Pomerelia lay in eastern Pomerania: on the southern shore of the Baltic Sea and west of the Vistula and its delta. The area centered on the city of Gdańsk at the mouth of the Vistula...

 (the Polish Corridor
Polish Corridor
The Polish Corridor , also known as Danzig Corridor, Corridor to the Sea or Gdańsk Corridor, was a territory located in the region of Pomerelia , which provided the Second Republic of Poland with access to the Baltic Sea, thus dividing the bulk of Germany from the province of East...

), Greater Poland
Greater Poland
Greater Poland or Great Poland, often known by its Polish name Wielkopolska is a historical region of west-central Poland. Its chief city is Poznań.The boundaries of Greater Poland have varied somewhat throughout history...

 and Polish Upper Silesia in the first week. The Polish plan for border defence was proven a dismal failure. The German advance as a whole was not slowed. On 10 September, the Polish commander-in-chief—Marshal Edward Rydz-Śmigły—ordered a general retreat
Withdrawal (military)
A withdrawal is a type of military operation, generally meaning retreating forces back while maintaining contact with the enemy. A withdrawal may be undertaken as part of a general retreat, to consolidate forces, to occupy ground that is more easily defended, or to lead the enemy into an ambush...

 to the southeast, towards the so-called Romanian Bridgehead. Meanwhile, the Germans were tightening their encirclement of the Polish forces west of the Vistula (in the Łódź area and, still farther west, around Poznań
Poznan
Poznań is a city on the Warta river in west-central Poland, with a population of 556,022 in June 2009. It is among the oldest cities in Poland, and was one of the most important centres in the early Polish state, whose first rulers were buried at Poznań's cathedral. It is sometimes claimed to be...

) and also penetrating deeply into eastern Poland. Warsaw—under heavy aerial bombardment since the first hours of the war—was attacked on 9 September and was put under siege
Siege of Warsaw (1939)
The 1939 Battle of Warsaw was fought between the Polish Warsaw Army garrisoned and entrenched in the capital of Poland and the German Army...

 on 13 September. Around that time, advanced German forces also reached the city of Lwów, a major metropolis
Metropolis
A metropolis is a very large city or urban area which is a significant economic, political and cultural center for a country or region, and an important hub for regional or international connections and communications...

 in eastern Poland. 1,150 German aircraft bombed Warsaw on 24 September.
The largest battle during this campaign—the Battle of Bzura—took place near the Bzura
Bzura
Bzura is a river in central Poland, a tributary of the Vistula river , with a length of 166 kilometres and the basin area of 7,788 km2.-Towns and townships:*Zgierz*Aleksandrów Łódzki*Ozorków*Łęczyca*Łowicz*Sochaczew...

 river west of Warsaw and lasted from 9–19 September. Polish armies Poznań and Pomorze, retreating from the border area of the Polish Corridor, attacked the flank of the advancing German 8th Army, but the counterattack failed after initial success. After the defeat, Poland lost its ability to take the initiative and counterattack on a large scale. German air power was instrumental during the battle. The Luftwaffes offensive broke what remained of Polish resistance in an "awesome demonstration of air power". The Luftwaffe quickly destroyed the bridges across the Bzura River. Afterward, the Polish forces were trapped out in the open, and were attacked by wave after wave of Stukas, dropping 50 kg (110.2 lb) "light bombs" which caused huge numbers of casualties. The Polish anti-aircraft batteries
Anti-aircraft warfare
NATO defines air defence as "all measures designed to nullify or reduce the effectiveness of hostile air action." They include ground and air based weapon systems, associated sensor systems, command and control arrangements and passive measures. It may be to protect naval, ground and air forces...

 ran out of ammunition and retreated to the forests, but were then "smoked out" by the Heinkel He 111
Heinkel He 111
The Heinkel He 111 was a German aircraft designed by Siegfried and Walter Günter in the early 1930s in violation of the Treaty of Versailles. Often described as a "Wolf in sheep's clothing", it masqueraded as a transport aircraft, but its purpose was to provide the Luftwaffe with a fast medium...

 and Dornier Do 17
Dornier Do 17
The Dornier Do 17, sometimes referred to as the Fliegender Bleistift , was a World War II German light bomber produced by Claudius Dornier's company, Dornier Flugzeugwerke...

s dropping 100 kg (220.5 lb) incendiaries. The Luftwaffe left the army with the easy task of mopping up survivors. The Stukageschwaders alone dropped 388 t (427.7 ST) of bombs during this battle.

The Polish government (of President Ignacy Mościcki
Ignacy Moscicki
Ignacy Mościcki was a Polish chemist, politician, and President of Poland . He was the longest-serving President of Poland .-Life:...

) and the high command (of Marshal
Marshal of Poland
Marshal of Poland is the highest rank in the Polish Army. It has been granted to only six officers. At present, this rank is equivalent to a Field Marshal or General of the Army in other NATO armies.-History:...

 Edward Rydz-Śmigły) left Warsaw in the first days of the campaign and headed southeast, reaching Lublin on 6 September. From there, it moved on 9 September to Kremenez, and on 13 September to Zaleshiki on the Romanian border. Rydz-Śmigły ordered the Polish forces to retreat in the same direction, behind the Vistula and San rivers, beginning the preparations for the long defence of the Romanian Bridgehead area.

Phase 2: Soviet invasion

From the beginning, the German government repeatedly asked Vyacheslav Molotov
Vyacheslav Molotov
Vyacheslav Mikhailovich Molotov was a Soviet politician and diplomat, an Old Bolshevik and a leading figure in the Soviet government from the 1920s, when he rose to power as a protégé of Joseph Stalin, to 1957, when he was dismissed from the Presidium of the Central Committee by Nikita Khrushchev...

 whether the Soviet Union would keep to its side of the partition bargain. Soviet forces attacked Poland on 17 September. It was agreed that the USSR would relinquish its interest in the territories between the new border and Warsaw in exchange for inclusion of Lithuania
Lithuania
Lithuania , officially the Republic of Lithuania is a country in Northern Europe, the biggest of the three Baltic states. It is situated along the southeastern shore of the Baltic Sea, whereby to the west lie Sweden and Denmark...

 in the Soviet "zone of interest".

By 17 September, the Polish defence was already broken and the only hope was to retreat and reorganize along the Romanian Bridgehead. However, these plans were rendered obsolete nearly overnight, when the over 800,000 strong Soviet Red Army
Red Army
The Workers' and Peasants' Red Army started out as the Soviet Union's revolutionary communist combat groups during the Russian Civil War of 1918-1922. It grew into the national army of the Soviet Union. By the 1930s the Red Army was among the largest armies in history.The "Red Army" name refers to...

 entered and created the Belarussian and Ukrainian fronts
Front (Soviet Army)
A front was a major military organization in the Soviet Army during many wars. It was roughly equivalent to an army group in the militaries of most other countries except Germany...

 after invading the eastern regions of Poland
Kresy
The Polish term Kresy refers to a land considered by Poles as historical eastern provinces of their country. Today, it makes western Ukraine, western Belarus, as well as eastern Lithuania, with such major cities, as Lviv, Vilnius, and Hrodna. This territory belonged to the Polish-Lithuanian...

 in violation of the Riga Peace Treaty, the Soviet-Polish Non-Aggression Pact
Soviet-Polish Non-Aggression Pact
The Soviet–Polish Non-Aggression Pact ) was an international treaty of non-aggression signed in 1932 by representatives of Poland and the USSR. The pact was unilaterally broken by the Soviet Union on September 17, 1939, during the Nazi and Soviet invasion of Poland.-Background:After the...

, and other international treaties, both bilateral and multilateral. Soviet diplomacy claimed that they were "protecting the Ukrainian
Ukrainians
Ukrainians are an East Slavic ethnic group native to Ukraine, which is the sixth-largest nation in Europe. The Constitution of Ukraine applies the term 'Ukrainians' to all its citizens...

 and Belarusian
Belarusians
Belarusians ; are an East Slavic ethnic group who populate the majority of the Republic of Belarus. Introduced to the world as a new state in the early 1990s, the Republic of Belarus brought with it the notion of a re-emerging Belarusian ethnicity, drawn upon the lines of the Old Belarusian...

 minorities of eastern Poland since the Polish government had abandoned the country and the Polish state ceased to exist".

Polish border defence forces in the east—known as the Korpus Ochrony Pogranicza—consisted of about 25 battalions. Edward Rydz-Śmigły ordered them to fall back and not engage the Soviets. This, however, did not prevent some clashes and small battles, such as the Battle of Grodno
Battle of Grodno (1939)
The Battle of Grodno took place between 21 September and 24 September 1939, during the Soviet invasion of Poland. It was fought between improvised Polish units under Gen...

, as soldiers and local population attempted to defend the city. The Soviets murdered numerous Polish officers, including prisoners of war
Prisoner of war
A prisoner of war or enemy prisoner of war is a person, whether civilian or combatant, who is held in custody by an enemy power during or immediately after an armed conflict...

 like General Józef Olszyna-Wilczyński
Józef Olszyna-Wilczynski
Józef Konstanty Olszyna-Wilczyński was a Polish general and one of the high-ranking commanders of the Polish Army. A veteran of World War I, Polish-Ukrainian War and the Polish-Bolshevik War, he was murdered by the Soviets during the Polish Defensive War of 1939.-Early life:Józef Wilczyński was...

. The Organization of Ukrainian Nationalists
Organization of Ukrainian Nationalists
The Organization of Ukrainian Nationalists is a Ukrainian political organization which as a movement originally was created in 1929 in Western Ukraine . The OUN accepted violence as an acceptable tool in the fight against foreign and domestic enemies particularly Poland and Russia...

 rose against the Poles, and communist partisans organized local revolts, robbing and murdering Poles. Those movements were quickly disciplined by the NKVD
NKVD
The People's Commissariat for Internal Affairs was the public and secret police organization of the Soviet Union that directly executed the rule of power of the Soviets, including political repression, during the era of Joseph Stalin....

. The Soviet invasion was one of the decisive factors that convinced the Polish government that the war in Poland was lost. Prior to the Soviet attack from the east, the Polish military's fall-back plan had called for long-term defence against Germany in the south-eastern part of Poland, while awaiting relief from a Western Allies attack on Germany's western border. However, the Polish government refused to surrender or negotiate a peace with Germany. Instead, it ordered all units to evacuate Poland and reorganize in France.
Meanwhile, Polish forces tried to move towards the Romanian Bridgehead area, still actively resisting the German invasion. From 17–20 September, Polish armies Kraków and Lublin were crippled at the Battle of Tomaszów Lubelski
Battle of Tomaszów Lubelski
Battle of Tomaszów Lubelski took place from 17 September to 26 September 1939 near the town of Tomaszów Lubelski. It was the second largest battle of the Invasion of Poland and also the largest tank battle of the campaign. It resulted in the destruction of the Polish forces...

, the second largest battle of the campaign. The city of Lwów capitulated on 22 September because of Soviet intervention; the city had been attacked by the Germans over a week earlier, and in the middle of the siege, the German troops handed operations over to their Soviet allies. Despite a series of intensifying German attacks, Warsaw—defended by quickly reorganized retreating units, civilian volunteers and militia
Militia
The term militia is commonly used today to refer to a military force composed of ordinary citizens to provide defense, emergency law enforcement, or paramilitary service, in times of emergency without being paid a regular salary or committed to a fixed term of service. It is a polyseme with...

—held out until 28 September. The Modlin Fortress
Modlin Fortress
Modlin Fortress is one of the biggest 19th century fortresses in Poland. It is located the town of Nowy Dwór Mazowiecki in district Modlin on the Narew river, some 50 kilometres north of Warsaw...

 north of Warsaw capitulated on 29 September after an intense 16-day battle
Battle of Modlin
The Battle of Modlin took place during the German invasion of Poland at the beginning of the Second World War. Modlin Fortress was initially the headquarters of the Modlin Army until its retreat eastwards. From 13 September to 29 September in 1939 it served as a defensive citadel for Polish forces...

. Some isolated Polish garrison
Garrison
Garrison is the collective term for a body of troops stationed in a particular location, originally to guard it, but now often simply using it as a home base....

s managed to hold their positions long after being surrounded by German forces. Westerplatte
Westerplatte
Westerplatte is a peninsula in Gdańsk, Poland, located on the Baltic Sea coast mouth of the Dead Vistula , in the Gdańsk harbour channel...

 enclave's tiny garrison capitulated on 7 September and the Oksywie
Oksywie
Oksywie is a neighbourhood of the city of Gdynia, Pomeranian Voivodeship, northern Poland. Formerly a separate settlement, it is actually several centuries older than the city it is a part of currently.-Etymology:...

 garrison held
Battle of Kepa Oksywska
The Battle of Kępa Oksywska took place in the Oksywie Heights outside of the city of Gdynia between September 10 and September 19, 1939. The battle, fought by the Polish Army and the German Wehrmacht, was part of the Polish September Campaign during World War II...

 until 19 September; Hel Fortified Area
Hel Fortified Area
The Hel Fortified Area was a set of Polish fortifications, constructed on the Hel Peninsula in northern Poland, in close proximity to the interwar border of Poland and the Third Reich. It was created in 1936, upon a decree of President Ignacy Moscicki...

 was defended
Battle of Hel
The Battle of Hel was one of the longest battles of the Invasion of Poland during World War II.The Hel Peninsula, together with the town of Hel, was the pocket of Polish Army resistance that held out the longest against the German invasion...

 until 2 October. In the last week of September, Hitler made a speech in the city of Danzig in which he said:
Poland never will rise again in the form
Second Polish Republic
The Second Polish Republic, Second Commonwealth of Poland or interwar Poland refers to Poland between the two world wars; a period in Polish history in which Poland was restored as an independent state. Officially known as the Republic of Poland or the Commonwealth of Poland , the Polish state was...

 of the Versailles treaty
Treaty of Versailles
The Treaty of Versailles was one of the peace treaties at the end of World War I. It ended the state of war between Germany and the Allied Powers. It was signed on 28 June 1919, exactly five years after the assassination of Archduke Franz Ferdinand. The other Central Powers on the German side of...

. That is guaranteed not only by Germany
Nazi Germany
Nazi Germany , also known as the Third Reich , but officially called German Reich from 1933 to 1943 and Greater German Reich from 26 June 1943 onward, is the name commonly used to refer to the state of Germany from 1933 to 1945, when it was a totalitarian dictatorship ruled by...

, but also… Russia
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

.


Despite a Polish victory at the Battle of Szack
Battle of Szack
Battle of Szack was one of the major battles between the Polish Army and the Red Army fought in 1939 in the beginning the Second World War.- Eve of the Battle :...

, after which the Soviets executed all the officers and NCOs
Non-commissioned officer
A non-commissioned officer , called a sub-officer in some countries, is a military officer who has not been given a commission...

 they had captured, the Red Army reached the line of rivers Narew
Narew
The Narew River , in western Belarus and north-eastern Poland, is a left tributary of the Vistula river...

, Bug River, Vistula and San by 28 September, in many cases meeting German units advancing from the other direction. Polish defenders on the Hel peninsula
Hel Peninsula
Hel Peninsula |Nehrung]]) is a 35-km-long sand bar peninsula in northern Poland separating the Bay of Puck from the open Baltic Sea. It is located in Puck County of the Pomeranian Voivodeship.- Geography :...

 on the shore of the Baltic Sea
Baltic Sea
The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...

 held out until 2 October. The last operational unit of the Polish Army, General Franciszek Kleeberg
Franciszek Kleeberg
Franciszek Kleeberg was a Polish general. He served in the Austro-Hungarian Army before joining the Polish Legions in World War I and later the Polish Army. During the German Invasion of Poland he commanded Independent Operational Group Polesie...

's Samodzielna Grupa Operacyjna "Polesie"
Independent Operational Group Polesie
Independent Operational Group Polesie was one of the Polish Army Corps that defended Poland during the Invasion of Poland in 1939. It was created on 11 September 1939 and was commanded by general Franciszek Kleeberg...

, surrendered after the four-day Battle of Kock
Battle of Kock (1939)
The Battle of Kock, was the final battle in the Invasion of Poland at the beginning of World War II. It took place between 2–5 October 1939, near the town of Kock, in Poland....

 near Lublin
Lublin
Lublin is the ninth largest city in Poland. It is the capital of Lublin Voivodeship with a population of 350,392 . Lublin is also the largest Polish city east of the Vistula river...

 on 6 October marking the end of the September Campaign.

Civilian losses

The Polish September Campaign was an instance of total war
Total war
Total war is a war in which a belligerent engages in the complete mobilization of fully available resources and population.In the mid-19th century, "total war" was identified by scholars as a separate class of warfare...

. Consequently, civilian casualties were high during and after combat. From the start, the Luftwaffe attacked civilian targets and columns of refugees along the roads to wreak havoc, disrupt communications, and target Polish morale. Apart from the victims of the battles, it is alleged that the German forces (both SS and the regular Wehrmacht) murdered several thousand Polish civilians. Also, during Operation Tannenberg
Operation Tannenberg
Operation Tannenberg was the codename for one of the extermination actions directed at the Polish people during World War II, part of the Generalplan Ost...

, nearly 20,000 Poles were shot at 760 mass execution sites by the Einsatzgruppen
Einsatzgruppen
Einsatzgruppen were SS paramilitary death squads that were responsible for mass killings, typically by shooting, of Jews in particular, but also significant numbers of other population groups and political categories...

.

Altogether, the civilian losses of Polish population amounted to about 150,000–200,000 while German civilian losses amounted to roughly 3,250 (including 2,000 who died fighting Polish troops as members of a fifth column
Fifth column
A fifth column is a group of people who clandestinely undermine a larger group such as a nation from within.-Origin:The term originated with a 1936 radio address by Emilio Mola, a Nationalist General during the 1936–39 Spanish Civil War...

).

Aftermath

Poland was divided among Germany, the Soviet Union, and Slovakia. Lithuania received the city of Wilno and its environs on 28 October 1939 from the Soviet Union. On 8 and 13 September 1939, the German military districts
German military administration in occupied Poland
German military administration in occupied Poland refers to the brief period during and in the immediate aftermath of the German invasion of Poland , in which the occupied Polish territories were administered by the German military, instead of civilian, administration.-Military administration:On 8...

 of "Posen" (Poznan)—commanded by General Alfred von Vollard-Bockelberg—and "Westpreußen" (West Prussia)—commanded by General Walter Heitz
Walter Heitz
Walter Heitz was a German Generaloberst, serving during World War II. Heitz commanded the VIII. Armeekorps on the Eastern Front...

—were established in conquered Greater Poland
Greater Poland
Greater Poland or Great Poland, often known by its Polish name Wielkopolska is a historical region of west-central Poland. Its chief city is Poznań.The boundaries of Greater Poland have varied somewhat throughout history...

 and Pomerelia
Pomerelia
Pomerelia is a historical region in northern Poland. Pomerelia lay in eastern Pomerania: on the southern shore of the Baltic Sea and west of the Vistula and its delta. The area centered on the city of Gdańsk at the mouth of the Vistula...

, respectively. Based on laws of 21 May 1935 and 1 June 1938, the German Wehrmacht
Wehrmacht
The Wehrmacht – from , to defend and , the might/power) were the unified armed forces of Nazi Germany from 1935 to 1945. It consisted of the Heer , the Kriegsmarine and the Luftwaffe .-Origin and use of the term:...

shared its administrative powers with civilian "chief civil administrators" (Chefs der Zivilverwaltung, CdZ). German dictator Adolf Hitler
Adolf Hitler
Adolf Hitler was an Austrian-born German politician and the leader of the National Socialist German Workers Party , commonly referred to as the Nazi Party). He was Chancellor of Germany from 1933 to 1945, and head of state from 1934 to 1945...

 appointed Arthur Greiser
Arthur Greiser
Arthur Greiser was a Nazi German politician and SS Obergruppenfuhrer. He was one of the persons primarily responsible for organizing the Holocaust in Poland and numerous other war crimes and crimes against humanity, for which he was tried, convicted and executed by hanging after World War...

 to become the CdZ of the Posen military district, and Danzig
Free City of Danzig
The Free City of Danzig was a semi-autonomous city-state that existed between 1920 and 1939, consisting of the Baltic Sea port of Danzig and surrounding areas....

's Gauleiter
Gauleiter
A Gauleiter was the party leader of a regional branch of the NSDAP or the head of a Gau or of a Reichsgau.-Creation and Early Usage:...

Albert Forster
Albert Forster
Albert Maria Forster was a Nazi German politician. Under his administration as the Gauleiter of Danzig-West Prussia during the Second World War, the local non-German population suffered ethnic cleansing, mass murder, and forceful Germanisation...

 to become the CdZ of the West Prussian military district. On 3 October, the military districts "Lodz" and "Krakau" (Cracow) were set up under command of Generalobersten (Colonel-Generals)) Gerd von Rundstedt
Gerd von Rundstedt
Karl Rudolf Gerd von Rundstedt was a Generalfeldmarschall of the German Army during World War II. He held some of the highest field commands in all phases of the war....

 and Wilhelm List, and Hitler appointed Hans Frank
Hans Frank
Hans Michael Frank was a German lawyer who worked for the Nazi party during the 1920s and 1930s and later became a high-ranking official in Nazi Germany...

 and Arthur Seyß-Inquart as civil heads, respectively. At the same time, Frank was appointed "supreme chief administrator" for all occupied territories. On 28 September, another secret German-Soviet protocol modified the arrangements of August: all of Lithuania was shifted to the Soviet sphere of influence; in exchange, the dividing line in Poland was moved in Germany's favour, eastwards towards the Bug River
Bug River
The Bug River is a left tributary of the Narew river flows from central Ukraine to the west, passing along the Ukraine-Polish and Polish-Belarusian border and into Poland, where it empties into the Narew river near Serock. The part between the lake and the Vistula River is sometimes referred to as...

. On 8 October, Germany formally annexed the western parts of Poland
Polish areas annexed by Nazi Germany
At the beginning of World War II, nearly a quarter of the pre-war Polish areas were annexed by Nazi Germany and placed directly under German civil administration, while the rest of Nazi occupied Poland was named as General Government...

 with Greiser and Forster as Reichsstatthalter
Reichsstatthalter
The term Reichsstatthalter was used twice for different offices, in the imperial Hohenzollern dynasty's German Empire and the single-party Nazi Third Reich.- "Statthalter des Reiches" 1879-1918 in Alsace-Lorraine :...

, while the south-central parts were administered as the General Government
General Government
The General Government was an area of Second Republic of Poland under Nazi German rule during World War II; designated as a separate region of the Third Reich between 1939–1945...

 led by Frank.
Even though water barriers separated most of the spheres of interest, the Soviet and German troops met on numerous occasions. The most remarkable event of this kind occurred at Brest-Litovsk on 22 September. The German 19th Panzer Corps—commanded by General Heinz Guderian
Heinz Guderian
Heinz Wilhelm Guderian was a German general during World War II. He was a pioneer in the development of armored warfare, and was the leading proponent of tanks and mechanization in the Wehrmacht . Germany's panzer forces were raised and organized under his direction as Chief of Mobile Forces...

—had occupied the city, which lay within the Soviet sphere of interest. When the Soviet 29th Tank Brigade—commander by S. M. Krivoshein—approached, the commanders negotiated that the German troops would withdraw and the Soviet troops would enter the city saluting each other. At Brest-Litovsk, Soviet and German commanders held a joint victory parade before German forces withdrew westward behind a new demarcation line. Just three days earlier, however, the parties had a more hostile encounter near Lwow (Lviv
Lviv
Lviv is a city in western Ukraine. The city is regarded as one of the main cultural centres of today's Ukraine and historically has also been a major Polish and Jewish cultural center, as Poles and Jews were the two main ethnicities of the city until the outbreak of World War II and the following...

, Lemberg
), when the German 137th Gebirgsjägerregimenter (mountain infantry regiment) attacked a reconnaissance detachment of the Soviet 24th Tank Brigade; after a few casualties on both sides, the parties turned to negotiations. The German troops left the area, and the Red Army troops entered Lviv on 22 September.

About 65,000 Polish troops were killed in the fighting, with 420,000 others being captured by the Germans and 240,000 more by the Soviets (for a total of 660,000 prisoners). Up to 120,000 Polish troops escaped to neutral
Neutral country
A neutral power in a particular war is a sovereign state which declares itself to be neutral towards the belligerents. A non-belligerent state does not need to be neutral. The rights and duties of a neutral power are defined in Sections 5 and 13 of the Hague Convention of 1907...

 Romania
Romania
Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...

 (through the Romanian Bridgehead and Hungary
Hungary
Hungary , officially the Republic of Hungary , is a landlocked country in Central Europe. It is situated in the Carpathian Basin and is bordered by Slovakia to the north, Ukraine and Romania to the east, Serbia and Croatia to the south, Slovenia to the southwest and Austria to the west. The...

), and another 20,000 to Latvia
Latvia
Latvia , officially the Republic of Latvia , is a country in the Baltic region of Northern Europe. It is bordered to the north by Estonia , to the south by Lithuania , to the east by the Russian Federation , to the southeast by Belarus and shares maritime borders to the west with Sweden...

 and Lithuania, with the majority eventually making their way to France or Britain. Most of the Polish Navy succeeded in evacuating to Britain as well. German personnel losses were less than their enemies (~16,000 KIA
Killed in action
Killed in action is a casualty classification generally used by militaries to describe the deaths of their own forces at the hands of hostile forces. The United States Department of Defense, for example, says that those declared KIA need not have fired their weapons but have been killed due to...

).
Neither side—Germany, the Western Allies or the Soviet Union—expected that the German invasion of Poland would lead to a war that would surpass World War I in its scale and cost. It would be months before Hitler would see the futility of his peace negotiation attempts with Great Britain and France, but the culmination of combined European and Pacific conflicts would result in what was truly a "world war". Thus, what was not seen by most politicians and generals in 1939 is clear from the historical perspective: The Polish September Campaign marked the beginning of the Second World War in Europe
European Theatre of World War II
The European Theatre of World War II was a huge area of heavy fighting across Europe from Germany's invasion of Poland on September 1, 1939 until the end of the war with the German unconditional surrender on May 8, 1945...

, which combined with the Japanese invasion of China
Second Sino-Japanese War
The Second Sino-Japanese War was a military conflict fought primarily between the Republic of China and the Empire of Japan. From 1937 to 1941, China fought Japan with some economic help from Germany , the Soviet Union and the United States...

 in 1937 and the Pacific War
Pacific War
The Pacific War, also sometimes called the Asia-Pacific War refers broadly to the parts of World War II that took place in the Pacific Ocean, its islands, and in East Asia, then called the Far East...

 in 1941, formed the cataclysm known as World War II.

The invasion of Poland led to Britain and France to declare war on Germany on 3 September. However, they did little to affect the outcome of the September Campaign. This lack of direct help led many Poles to believe that they had been betrayed by their Western allies.

On 23 May 1939, Hitler explained to his officers that the object of the aggression was not Danzig, but the need to obtain German Lebensraum
Lebensraum
was one of the major political ideas of Adolf Hitler, and an important component of Nazi ideology. It served as the motivation for the expansionist policies of Nazi Germany, aiming to provide extra space for the growth of the German population, for a Greater Germany...

and details of this concept would be later formulated in the infamous Generalplan Ost
Generalplan Ost
Generalplan Ost was a secret Nazi German plan for the colonization of Eastern Europe. Implementing it would have necessitated genocide and ethnic cleansing to be undertaken in the Eastern European territories occupied by Germany during World War II...

. The invasion decimated urban
Urban area
An urban area is characterized by higher population density and vast human features in comparison to areas surrounding it. Urban areas may be cities, towns or conurbations, but the term is not commonly extended to rural settlements such as villages and hamlets.Urban areas are created and further...

 residential areas, civilians soon became indistinguishable from combatants, and the forthcoming German occupation (both on the annexed territories
Polish areas annexed by Nazi Germany
At the beginning of World War II, nearly a quarter of the pre-war Polish areas were annexed by Nazi Germany and placed directly under German civil administration, while the rest of Nazi occupied Poland was named as General Government...

 and in the General Government
General Government
The General Government was an area of Second Republic of Poland under Nazi German rule during World War II; designated as a separate region of the Third Reich between 1939–1945...

) was one of the most brutal episodes of World War II, resulting in between 5.47 million and 5.67 million Polish deaths (about 20% of the country's "total" population, and over 90% of its Jewish minority)—including the mass murder of 3 million Poles in extermination camps like Auschwitz, in concentration camps, and in numerous ad hoc massacres, where civilians were rounded up, taken to a nearby forest, machine-gunned, and then buried, whether they were dead or not.

According to the Polish Institute of National Remembrance, Soviet occupation
Polish areas annexed by the Soviet Union
Immediately after the German invasion of Poland in 1939, which marked the beginning of World War II, the Soviet Union invaded the eastern regions of the Second Polish Republic, which Poles referred to as the "Kresy," and annexed territories totaling 201,015 km² with a population of 13,299,000...

 between 1939 and 1941 resulted in the death of 150,000 and deportation
Deportation
Deportation means the expulsion of a person or group of people from a place or country. Today it often refers to the expulsion of foreign nationals whereas the expulsion of nationals is called banishment, exile, or penal transportation...

 of 320,000 of Polish citizens, when all who were deemed dangerous to the Soviet regime were subject to sovietization
Sovietization
Sovietization is term that may be used with two distinct meanings:*the adoption of a political system based on the model of soviets .*the adoption of a way of life and mentality modelled after the Soviet Union....

, forced resettlement, imprisonment in labor camp
Labor camp
A labor camp is a simplified detention facility where inmates are forced to engage in penal labor. Labor camps have many common aspects with slavery and with prisons...

s (the Gulag
Gulag
The Gulag was the government agency that administered the main Soviet forced labor camp systems. While the camps housed a wide range of convicts, from petty criminals to political prisoners, large numbers were convicted by simplified procedures, such as NKVD troikas and other instruments of...

s
) or murdered, like the Polish officers in the Katyn massacre
Katyn massacre
The Katyn massacre, also known as the Katyn Forest massacre , was a mass execution of Polish nationals carried out by the People's Commissariat for Internal Affairs , the Soviet secret police, in April and May 1940. The massacre was prompted by Lavrentiy Beria's proposal to execute all members of...

.

Misconceptions

There are several common misconceptions regarding the Polish September Campaign.
  • The Polish Army fought German tanks with horse-mounted cavalry wielding lances and swords.
In 1939, 10% of the Polish army was made up of cavalry units. Polish cavalry
Polish cavalry
The Polish cavalry can trace its origins back to the days of Medieval mounted knights. Poland had always been a country of flatlands and fields and mounted forces operate well in this environment...

 never charged German tanks or entrenched infantry or artillery, but usually acted as mobile infantry
Mobile infantry
Mobile infantry is one of several military terms usually referring to infantry units equipped with vehicles.Before the development of railroads in the 19th century, infantry armies got to the battlefield by walking, or sometimes by ship...

 (like dragoon
Dragoon
The word dragoon originally meant mounted infantry, who were trained in horse riding as well as infantry fighting skills. However, usage altered over time and during the 18th century, dragoons evolved into conventional light cavalry units and personnel...

s) and reconnaissance
Reconnaissance
Reconnaissance is the military term for exploring beyond the area occupied by friendly forces to gain information about enemy forces or features of the environment....

 units and executed cavalry charges only in rare situations against foot soldiers. Other armies (including German and Soviet) also fielded and extensively used elite horse cavalry units at that time. Polish cavalry consisted of eleven brigade
Brigade
A brigade is a major tactical military formation that is typically composed of two to five battalions, plus supporting elements depending on the era and nationality of a given army and could be perceived as an enlarged/reinforced regiment...

s, as emphasized by its military doctrine
Military doctrine
Military doctrine is the concise expression of how military forces contribute to campaigns, major operations, battles, and engagements.It is a guide to action, not hard and fast rules. Doctrine provides a common frame of reference across the military...

, equipped with anti tank rifles "UR" and light artillery such as the highly effective Bofors 37 mm
Bofors 37 mm
The Bofors 37 mm gun was an anti-tank gun designed by Swedish manufacturer Bofors in the early 1930s. Licensed copies were produced in a number of countries. The gun was used by some European armies during World War II, mainly at the early stage of the war.-Development history:The gun was...

 anti-tank gun
Anti-tank warfare
Anti-tank warfare was created by the need to seek technology and tactics to destroy tanks and their supporting infantry during the First World War...

. The myth originated from war correspondents reports of the Battle of Krojanty, where a Polish cavalry brigade was fired upon in ambush
Ambush
An ambush is a long-established military tactic, in which the aggressors take advantage of concealment and the element of surprise to attack an unsuspecting enemy from concealed positions, such as among dense underbrush or behind hilltops...

 by hidden armored vehicles, after it had mounted a sabre-charge against German infantry.Snidner takes issue here with this contention on at least one occasion. Seidner,Marshal Edward Śmigły-Rydz Rydz and the Defense of Poland
  • The Polish air force was destroyed on the ground in the first days of the war.
The Polish Air Force
Polish Air Force order of battle in 1939
The following is the order of battle of the Polish Air Force prior to the outbreak of the Polish Defensive War of 1939. During the mobilization waves of March and August of that year, all peace-time units were deployed to airfields throughout the country and attached to respective commands of Air...

, though numerically inferior, had been moved from air bases to small camouflaged airfields shortly before the war. Only some trainers and auxiliary aircraft were destroyed on the ground. The Polish Air Force, significantly outnumbered and with its fighters outmatched by more advanced German fighters, remained active up to the second week of the campaign, inflicting significant damage on the Luftwaffe. The Luftwaffe lost, to all operational causes, 285 aircraft, with 279 more damaged beyond repair, while the Poles lost 333 aircraft.
  • Poland offered little resistance and surrendered quickly.
In the first few days, Germany sustained very heavy losses: Poland cost the Germans an entire armored division, thousands of soldiers, and 25% of its air strength. As for duration, the September Campaign lasted only about one week less than the Battle of France
Battle of France
In the Second World War, the Battle of France was the German invasion of France and the Low Countries, beginning on 10 May 1940, which ended the Phoney War. The battle consisted of two main operations. In the first, Fall Gelb , German armoured units pushed through the Ardennes, to cut off and...

 in 1940, even though the Anglo-French forces were much closer to parity with the Germans in numerical strength and equipment.Polish to Germany forces in the September Campaign: 1,000,000 soldiers 4,300 guns, 880 tanks, 435 aircraft (Poland) to 1,800,000 soldiers, 10,000 guns, 2,800 tanks, 3,000 aircraft (Germany). French and participating Allies to German forces in the Battle of France: 2,862,000 soldiers, 13,974 guns, 3,384 tanks, 3,099 aircraft 2 (Allies) to 3,350,000 soldiers, 7,378 guns, 2,445 tanks, 5,446 aircraft (Germany). Furthermore, the Polish Army was preparing the Romanian Bridgehead
Romanian Bridgehead
The Romanian Bridgehead was an area in southeastern Poland, now located in Ukraine. During the Polish Defensive War of 1939 , on September 14 the Polish Commander in Chief Marshal of Poland Edward Rydz-Śmigły ordered all Polish troops fighting east of the Vistula to withdraw towards Lwów, and...

, which would have prolonged Polish defence, but this plan was cancelled due to the Soviet invasion of Poland on 17 September 1939. Poland also never officially surrendered to the Germans. Under German occupation, the Polish army continued to fight underground, as Armia Krajowa
Armia Krajowa
The Armia Krajowa , or Home Army, was the dominant Polish resistance movement in World War II German-occupied Poland. It was formed in February 1942 from the Związek Walki Zbrojnej . Over the next two years, it absorbed most other Polish underground forces...

 and forest partisans—Leśni
Leśni
Leśni is one of the informal names applied to the anti-German partisan groups operating in occupied Poland during World War II. The groups were formed mostly by people who for various reasons could not operate from settlements they lived in and had to retreat to the forests...

. The Polish resistance movement in World War II
Polish resistance movement in World War II
The Polish resistance movement in World War II, with the Home Army at its forefront, was the largest underground resistance in all of Nazi-occupied Europe, covering both German and Soviet zones of occupation. The Polish defence against the Nazi occupation was an important part of the European...

 in German-occupied Poland was one of the largest resistance movements in all of occupied Europe.

  • Blitzkrieg
    Blitzkrieg
    For other uses of the word, see: Blitzkrieg Blitzkrieg is an anglicized word describing all-motorised force concentration of tanks, infantry, artillery, combat engineers and air power, concentrating overwhelming force at high speed to break through enemy lines, and, once the lines are broken,...

     was first used in Poland
    .
It is often assumed that blitzkrieg is the strategy that Germany first used in Poland. Many early post-war histories, such as Barrie Pitt's in The Second World War (BPC Publishing 1966), attribute German victory to "enormous development in military technique which occurred between 1918 and 1940", citing that "Germany, who translated (British inter-war) theories into action… called the result Blitzkrieg." This idea has been repudiated by some authors. Matthew Cooper writes: "Throughout the Polish Campaign, the employment of the mechanized units revealed the idea that they were intended solely to ease the advance and to support the activities of the infantry…. Thus, any strategic exploitation of the armoured idea was still-born. The paralysis of command and the breakdown of morale were not made the ultimate aim of the … German ground and air forces, and were only incidental by-products of the traditional manoeuvers of rapid encirclement and of the supporting activities of the flying artillery of the Luftwaffe
Luftwaffe
Luftwaffe is a generic German term for an air force. It is also the official name for two of the four historic German air forces, the Wehrmacht air arm founded in 1935 and disbanded in 1946; and the current Bundeswehr air arm founded in 1956....

, both of which had as their purpose the physical destruction of the enemy troops. Such was the Vernichtungsgedanke
Vernichtungsgedanke
Vernichtungsgedanke, literally meaning "concept of annihilation" in German and generally taken to mean "the concept of fast annihilation of enemy forces" is a tactical doctrine dating back to Frederick the Great. It emphasizes rapid, fluid movement to unbalance an enemy, allowing the attacker to...

of the Polish campaign." Vernichtungsgedanke was a strategy dating back to Frederick the Great, and was applied in the Polish Campaign little changed from the French campaigns in 1870
Franco-Prussian War
The Franco-Prussian War or Franco-German War, often referred to in France as the 1870 War was a conflict between the Second French Empire and the Kingdom of Prussia. Prussia was aided by the North German Confederation, of which it was a member, and the South German states of Baden, Württemberg and...

 or 1914. The use of tank
Tank
A tank is a tracked, armoured fighting vehicle designed for front-line combat which combines operational mobility, tactical offensive, and defensive capabilities...

s "left much to be desired...Fear of enemy action against the flanks of the advance, fear which was to prove so disastrous to German prospects in the west in 1940 and in the Soviet Union in 1941, was present from the beginning of the war."" John Ellis, writing in Brute Force
Brute Force (book)
Brute Force: Allied Strategy and Tactics in the Second World War is a book by historian John Ellis which concludes that the Allied Forces won World War II not by the skill of their leaders, war planners and commanders in the field, but by brute force...

asserted that "…there is considerable justice in Matthew Cooper's assertion that the panzer divisions were not given the kind of strategic (emphasis in original) mission that was to characterize authentic armoured blitzkrieg, and were almost always closely subordinated to the various mass infantry armies." Zaloga and Madej, in The Polish Campaign 1939, also address the subject of mythical interpretations of Blitzkrieg and the importance of other arms in the campaign. "Whilst Western accounts of the September campaign have stressed the shock value of the panzers and Stuka attacks, they have tended to underestimate the punishing effect of German artillery (emphasis added) on Polish units. Mobile and available in significant quantity, artillery shattered as many units as any other branch of the Wehrmacht."

See also

  • Polish resistance movement in World War II
    Polish resistance movement in World War II
    The Polish resistance movement in World War II, with the Home Army at its forefront, was the largest underground resistance in all of Nazi-occupied Europe, covering both German and Soviet zones of occupation. The Polish defence against the Nazi occupation was an important part of the European...

  • Armenian quote
    Armenian quote
    The Armenian quote is a paragraph understood to have been included in a speech by Adolf Hitler to Wehrmacht commanders at his Obersalzberg home on August 22, 1939, a week before the German invasion of Poland...

  • History of Poland (1939–1945)
    History of Poland (1939–1945)
    The history of Poland from 1939 to 1945 encompasses the German invasion of Poland as well as the Soviet invasion of Poland through to the end of World War II. On 1 September 1939, without a formal declaration of war, Germany invaded Poland...

  • Horses in World War II
    Horses in World War II
    Horses in World War II were used by the belligerent nations for transportation of troops, artillery, materiel, and, to a lesser extent, in mobile cavalry troops. The role of horses for each nation depended on its military strategy and state of economy and was most pronounced in German and Soviet...

  • List of Polish divisions in World War II
  • Occupation of Poland (1939–1945)
  • Oder-Neisse line
    Oder-Neisse line
    The Oder–Neisse line is the border between Germany and Poland which was drawn in the aftermath of World War II. The line is formed primarily by the Oder and Lusatian Neisse rivers, and meets the Baltic Sea west of the seaport cities of Szczecin and Świnoujście...

  • Phoney War
  • Polish cavalry brigade order of battle in 1939
    Polish cavalry brigade order of battle in 1939
    The following is a standard order of battle of the Polish cavalry brigade in 1939.-Chain of command :-Composition and armament:The following is a list of all equipment, armament, men and means of transport in use by a cavalry regiment and a cavalry brigade of the Polish Army, as of 1939...

  • Polish contribution to World War II
    Polish contribution to World War II
    The European theater of World War II opened with the German invasion of Poland on September 1, 1939. The Polish Army was defeated after over a month of fighting. After Poland had been overrun, a government-in-exile , armed forces, and an intelligence service were established outside of Poland....

  • Siege of Warsaw (1939)
    Siege of Warsaw (1939)
    The 1939 Battle of Warsaw was fought between the Polish Warsaw Army garrisoned and entrenched in the capital of Poland and the German Army...

  • Timeline of the Invasion of Poland (1939)
    Timeline of the Invasion of Poland (1939)
    - September :- September :- September ::1: World War II begins with the invasion of Poland by Nazi Germany. The resulting Invasion of Poland lasts until October 6, 1939, when the final significant Polish military forces surrender at Kock...

  • War crimes of the Wehrmacht
    War crimes of the Wehrmacht
    War crimes of the Wehrmacht were those carried out by the German armed forces during World War II. While the principal perpetrators of the Holocaust amongst German armed forces were the Nazi German 'political' armies , the regular armed forces represented by the Wehrmacht committed war crimes of...

  • Western betrayal
    Western betrayal
    Western betrayal, also called Yalta betrayal, refers to a range of critical views concerning the foreign policies of several Western countries between approximately 1919 and 1968 regarding Eastern Europe and Central Europe...


Citations

External links

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