National Defense was a volunteer military formation 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...

.

Its units (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 and demi-brigade

Demi-brigade

Not to be confused with 13th Demi-Brigade of the Foreign LegionThe Demi-brigade was a military formation first used by the French Army during the French Revolutionary Wars. The Demi-brigade amalgamated the various infantry organizations of the French Revolutionary infantry into a single unit...

s, divided into battalion

Battalion

A battalion is a military unit of around 300–1,200 soldiers usually consisting of between two and seven companies and typically commanded by either a Lieutenant Colonel or a Colonel...

s) were subordinated to various Polish corps

Corps

A corps is either a large formation, or an administrative grouping of troops within an armed force with a common function such as Artillery or Signals representing an arm of service...

 and armies.

National Defense is most commonly referred through its units (brigades - sing. Brygada Obrony Narodowej (Brygada ON) or battalions - sing. Batalion Obrony Narodowej (Batalion ON); the units were also named by the geographical region they were related to, and if more than one was formed, by roman numerals, ex. Batalion ON "Lwów II")

National Defense units were composed of volunteers, some reservists

Military reserve

A military reserve, tactical reserve, or strategic reserve is a group of military personnel or units which are initially not committed to a battle by their commander so that they are available to address unforeseen situations or exploit suddenly developing...

 and unemployed. They were equipped with second-grade weaponry, and their goal was to support defensive operations of the regular Polish Army. National Defense was created by an order of the Polish Minister of Defense on 5 December, 1936; the brigades begun to be formed in 1937.

During the German invasion of Poland in 1939 National Defense mobilized 83 battalions (approximately 1600 officers and 50 000 soldiers).

Brigades

I DOK: Warszawska Brygada Obrony Narodowej (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...

 Brigade of National Defense)

II DOK: Wołyńska Półbrygada Obrony Narodowej (Volhynia

Volhynia

Volhynia, Volynia, or Volyn is a historic region in western Ukraine located between the rivers Prypiat and Southern Bug River, to the north of Galicia and Podolia; the region is named for the former city of Volyn or Velyn, said to have been located on the Southern Bug River, whose name may come...

n Demi-Brigade of National Defense)

III DOK: Dziśnieńska Półbrygada Obrony Narodowej (Dzisna

Dzisna

Dzisna , is a town in the Vitsebsk Voblast of Belarus. It's located on the left bank of the Daugava River, near the confluence of Dysna. It has 2,700 inhabitants . The towns population has declined over the years; early in the 20th century it had close to 10,000 inhabitants....

 Half-Brigade of National Defense)

IV DOK: Sieradzka Brygada Obrony Narodowej (Sieradz

Sieradz

Sieradz is a town on the Warta river in central Poland with 44,326 inhabitants . It is situated in the Łódź Voivodship , but was previously the eponymous capital of the Sieradz Voivodship , and historically one of the minor duchies in Greater Poland.It is one of the oldest towns in Poland,...

 Brigade of National Defense)

V DOK: Dąbrowska Brygada Obrony Narodowej, Górnośląska Brygada Obrony Narodowej, Podhalańska Brygada Obrony Narodowej, Śląsko-Cieszyńska Brygada Obrony Narodowej (Dąbrowa Górnicza

Dabrowa Górnicza

Dąbrowa Górnicza is a city in Zagłębie Dąbrowskie in southern Poland, nearby Katowice. The north-east district of the Upper Silesian Metropolitan Union - metropolis with the population of almost 3 millions...

 Brigade of National Defense, 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...

n Brigade of National Defense, Podhale

Podhale

The Podhale is Poland's most southern region, sometimes referred to as the "Polish highlands". The Podhale is located in the foothills of the Tatra range of the Carpathian mountains, and is characterized by a rich tradition of folklore that is much romanticized in the Polish patriotic imagination...

 Brigade of National Defense, Cieszyn

Cieszyn

Cieszyn is a border-town and the seat of Cieszyn County, Silesian Voivodeship, southern Poland. It has 36,109 inhabitants . Cieszyn lies on the Olza River, a tributary of the Oder river, opposite Český Těšín....

 Silesia Brigade of National Defense)

VI DOK: Lwowska Brygada Obrony Narodowej, Tarnopolska Półbrygada Obrony Narodowej (Lwów Brigade of National Defense, Tarnopol Half-Brigade of National Defense)

VII DOK: Poznańska Brygada Obrony Narodowej, Kaliska Brygada Obrony Narodowej (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...

 Brigade of National Defense, Kalisz

Kalisz

Kalisz is a city in central Poland with 106,857 inhabitants , the capital city of the Kalisz Region. Situated on the Prosna river in the southeastern part of the Greater Poland Voivodeship, the city forms a conurbation with the nearby towns of Ostrów Wielkopolski and Nowe Skalmierzyce...

 Brigade of National Defense)

VIII DOK: Chełmińska Brygada Obrony Narodowej, Morska Brygada Obrony Narodowej, Pomorska Brygada Obrony Narodowej (Chełm Brigade of National Defense, Sea Brigade of National Defense, Pomorze Brigade of National Defense)

X DOK: Karpacka Brygada Obrony Narodowej, Podkarpacka Brygada Obrony Narodowej (Carpathian Brigade of National Defense, Subcarpathian Brigade of National Defense)

Brigades:
Chełmińska Brygada ON •
Cieszyńska Brygada ON •
Dąbrowska Brygada ON •
Kaliska Brygada ON •
Karpacka Brygada ON •
Lwowska Brygada ON •
Morska Brygada ON •
Podhalańska Brygada ON •
Podkarpacka Brygada ON •
Pomorska Brygada ON •
Poznańska Brygada ON •
Sieradzka Brygada ON •
Śląska Brygada ON •
Warszawska Brygada ON

Battalions:
Bielsko •
Brodnica •
Brzozów •
Bydgoszcz •
Chełm •
Chrzanów •
Cieszyn I •
Cieszyn II •
Czersk •
Dąbrowa Górnicza •
Gdynia I •
Gdynia II •
Gdynia III •
Grudziądz •
Huculski I •
Huculski II •
Jabłonowo •
Jarosław •
Jasło •
Kartuzy IV •
Kaszuby V •
Katowice •
Kcynia •
Kępno •
Kłobuck •
Koronowo •
Kościan •
Kościerzyna •
Kowel •
Koźmin •
Krosno •
Krotoszyn •
Leszno •
Limanowa •
Lubliniec •
Lwów I •
Lwów II •
Łuck •
Mazurski I •
Mazurski II •
Nakło •
Nowy Sącz •
Oborniki •
Olkusz •
Opalenica •
Ostrów •
Ostrzeszów •
Oświęcim •
Poznań I •
Poznań II •
Przemyśl •
Rawicz •
Rybnik •
Rzeszów •
Sambor •
Sanok •
Sosnowiec •
Stanisławów •
Starogard •
Stry •
Szamotuły •
Świecie •
Tarnowskie Góry •
Tuchola •
Turka •
Warszawski I •
Warszawski II •
Warszawski III •
Wągrowiec •
Wieluń I •
Wieluń II •
Zakopane •
Zawiercie •
Żnin •
Żywiec