Showing Dilly: The Man Who Broke Enigmas by Mavis Batey

The highly eccentric Alfred Dillwyn Knox, known simply as 'Dilly', was one of the leading figures in the British codebreaking successes of the two world wars. During the first, he was the chief codebreaker in the Admiralty, breaking the German navy's main flag code, before going on to crack the German Enigma ciphers during the Second World War at Bletchley Park. Here he enjoyed the triumphant culmination of his life's work: a reconstruction of the Enigma machine used by the Abwehr, the German Secret Service. This ensured the British were fully aware of what the German commanders knew about the Allied plans for the invasion of Europe, allowing MI5 and MI6 to use captured German spies to feed false information back to the Nazi spymasters. Dilly's codebreaking skills played a vital part in the deception operation that ensured the success of the D-Day landings.