The Battle of the Atlantic was the longest Battle of the entire war. It started the day that Neville Chamberlain declared war on Germany. It ended on the day that Germany surrendered five-and-a-half years later.

The Battle accounted for (on all sides) over 100,000 casualties and the loss of over 3,500 merchant ships and over 1,000 warships (including U-Boats).The conflict in the Atlantic Ocean is perceived as bringing Britain to the point of starvation and nearly leaving the country without the necessary resources to continue fighting the war.