Breaking Enigma

The real breakthrough came in 1944, when the British Navy captured a German submarine and its crew. They also captured an Enigma machine and the codebook used by the German navy to set the machines each day. This discovery was treated as top secret: if the Germans ever found out that the British had this information, they would have certainly changed all of their codes.

With the code books, the Enigma machine, Colossus and the expertise of the code breaking team, the British were now able to easily decode all of the German messages they intercepted. The information they managed to get about the German's plans undoubtedly helped the British and their Allies to win the war, and possibly even shortened it by a year or more.