The First Happy Time was a phase of the Battle of the Atlantic during which Germany Navy

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 It superseded the Kaiserliche Marine of World War I and the post-war Reichsmarine.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...

 U-boat

U-boat

U-boat is the anglicized version of the German word U-Boot , itself an abbreviation of Unterseeboot , and refers to military submarines operated by Germany, particularly in World War I and World War II...

s enjoyed significant success against 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...

 and its allies

Western Allies

The Western Allies were a political and geographic grouping among the Allied Powers of the Second World War. It generally includes the United Kingdom and British Commonwealth, the United States, France and various other European and Latin American countries, but excludes China, the Soviet Union,...

. It started in July 1940, almost immediately after France

French Third Republic

The French Third Republic was the republican government of France from 1870, when the Second French Empire collapsed due to the French defeat in the Franco-Prussian War, to 1940, when France was overrun by Nazi Germany during World War II, resulting in the German and Italian occupations of France...

, the United Kingdom's primary ally, was conquered by Germany

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...

 (the fall of France meant that the German U-boat fleet was brought closer to the British shipping lanes in the Atlantic). When it ended is a matter of interpretation, with some sources claiming October 1940 and others extending it to April, 1941. The reason for this successful German period was the British lack of radar

Radar

Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

-equipped ships, which meant that the U-boats were very hard to detect when they made nighttime surface attacks (sonar

Sonar

Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...

 could detect submerged U-boats).

From July 1940 to the end of October, 282 Allied ships were sunk off of the north-west approaches of Ireland

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

 for a loss of 1,489,795 tons of merchant shipping.

End of the First Happy Time

Various dates and reasons for the end of the First Happy Time include:

• March 1941, with the German loss of three prominent U-boat aces: Günther Prien
  Günther Prien
  Lieutenant Commander Günther Prien was one of the outstanding German U-boat aces of the first part of the Second World War, and the first U-boat commander to win the Knight's Cross of the Iron Cross. Under Prien's command, the submarine sank over 30 Allied ships totaling about...
  
  , Joachim Schepke
  Joachim Schepke
  Lieutenant-Commander Joachim Schepke was a German U-boat commander during World War II. He was the seventh recipient of the Knight's Cross of the Iron Cross with Oak Leaves . The Knight's Cross of the Iron Cross and its higher grade Oak Leaves was awarded by the Third Reich to recognise extreme...
  
   and Otto Kretschmer
  Otto Kretschmer
  Flotilla Admiral Otto Kretschmer was a German U-boat commander in the Second World War and later an admiral in the Bundesmarine. From September 1939 until being captured in March 1941, he sank 47 ships, a total of 274,333 tons. For this he received the Knight's Cross of the Iron Cross with Oak...
  
  .

See also

• Second Happy Time
  Second happy time
  The Second Happy Time , also known among German submarine commanders as the "American shooting season" was the informal name for a phase in the Second Battle of the Atlantic during which Axis submarines attacked merchant shipping along the east coast of North America...
  
  
• Operation Berlin
• Convoy SC-7
  Convoy SC-7
  SC-7 was the code name for a large Allied World War II convoy of 35 merchant ships and six escorts which sailed eastbound from Sydney, Nova Scotia for Liverpool and other United Kingdom ports on 5 October 1940. While crossing the Atlantic, the convoy was intercepted by one of the German Navy's...
  
  
• Convoy HX-84
  Convoy HX-84
  HX-84 was a North Atlantic convoy of the HX series during the battle of the Atlantic in World War II. It consisted of 38 merchant ships which sailed eastbound from Halifax, Nova Scotia, for Liverpool, England, on 28 October 1940 and was escorted by the armed merchant cruiser HMS Jervis Bay-The...
  
  
• Convoy HX-106
  Convoy HX-106
  Convoy HX-106 consisted of some 41 ships, eastbound from Halifax, Nova Scotia to Liverpool, England. The use of convoys was a standard tactic throughout the Battle of the Atlantic as a defence against U-boats and German commerce raiders....
  
  
• Convoy HX-112
  Convoy HX-112
  HX 112 was a North Atlantic convoy of the HX series which ran during the battle of the Atlantic in the Second World War. It was notable in that it saw the loss of U-boats commanded by two of the Kriegsmarine's foremost U-boat aces, U-99 with Korvettenkapitän Otto Kretschmer and U-100 with...
  
  
• Convoy OB-293
  Convoy OB-293
  OB 293 was a North Atlantic convoy which ran during the battle of the Atlantic in World War II.It was notable for seeing the loss to the Kriegsmarine of , with her commander KL Günther Prien, the person responsible for the sinking of two years previously....