1939

 

September

 

Hours after Britain declared war on Germany, a German submarine torpedoed a British passenger ship going to Montreal, resulting in 112 people losing their lives.

 

First Convoy of 36 ships set sail across the Atlantic.

 

1940

 

September

 

German U-boats begin to travel in groups called “Wolf Packs”

 

October

 

First attack of Wolf Pack. Attacked a convoy of 35 merchant ships and 6 escort ships.

 

1941

 

May

 

After capturing German submarine U-110, British intelligence were able to get their first Enigma code machine and worked to crack the code.

 

First convoy crosses the Atlantic. HX129

 

 

 

1942

 

May

 

German U-boats made it to the Coast of North America. They attacked at the St. Lawrence River, and sank 22 ships.

 

June

 

The worst month for allied shipping losses. Over 800000 tonnes of resources were lost.

 

1943

 

With the Enigma Code cracked, British intelligence was able to better track German communications. British ships were gaining the upper hand by sending in more soldiers to fight and regain control of the Atlantic.

 

May

 

German Admiral Karl Donitz called his U-boats back German U-boats from the Atlantic.

 

1945

 

U-boats officially stop fighting and the battle is over.