The Battle of the Atlantic was the longest campaign in World War II. The conflict began when a German Submarine sunk a Montreal-bond Passenger Ship named SS Athenia. As war broke out between the Allies and Germany, the safety of British merchant ships soon became a huge problem. German submarines, known as U-Boats (Unterseebooten) posed a great threat to the Allied ships in the Atlantic as these submarines possessed great capabilities of carrying numerous torpedoes. Germany had planned to cut off all resources of Britain, hoping to starve and deprive them of resources. The fear of these consequences caused the initiation of the Convoy system, an arrangement where all Allied Merchant ships are to travel in a large group with naval protection. The Royal Canadian Navy (RCN) began with only 3000 men and 11 fighting ships in 1939 to 400 fighting ships and 100,000 men towards the end of the war. They took on the responsibility of protecting vulnerable merchant vessels during the time of the war. The RCN also contributed in breaking the shipping lanes of the German Stronghold, allowing equipment from Halifax and Sydney to successfully reach Britain in 1943. The Battle of the Atlantic lasted through the duration of WWII, ending on May 8, 1945.