The German Enigma encryption device was notoriously effective, until it was cracked thanks to actions like this one.
On this day one of Britain’s greatest successes in World War II took place. Indeed, Britain’s King George VI called that operation “the most important single event in the whole war at sea”. The British, namely, managed to capture the German submarine U-110, together with a fully preserved Enigma encryption device and a codebook.
The German Enigma encryption device was notoriously effective, until its functioning was cracked thanks to actions like this one. The German U-110 submarine was commanded by Fritz-Julius Lemp, bearing the naval rank of Kapitänleutnant. The U-110 was discovered by the sonar of British corvette HMS Aubretia, and then was attacked by British destroyers HMS Bulldog and HMS Broadway with depth charges.
The submarine was damaged and the German commander was forced to surface and order an evacuation. He expected the submarine would sink, but when he realized that she is remaining afloat, he swam back with the intent to destroy her, together with the codebook that remained aboard. He was killed in the attempt, and the British took possession of the submarine, the Enigma, and the codebook.