Churchill: Walking with Destiny

by Andrew Roberts

Also that same day – 22 May 1940 – the Allied cryptographers at Bletchley Park in Buckinghamshire broke the Luftwaffe code for the Enigma cipher machine. They would break the German naval code in June 1941 and the Wehrmacht code three months later.129 For much of the war this stream of decrypts, known by its special security classification Ultra, allowed the Allies to read many of the communications sent and received between the German High Command, Army High Command, Wehrmacht, Luftwaffe, Kriegsmarine, SS, Abwehr (intelligence) and the Reichsbahn (railways). All told, several million communications were intercepted and decoded from the correspondence of the Führer himself right down to that of the harbour-master of Olbia in Sardinia (when Italian ciphers were broken in July 1941). The Bletchley code-breakers – as many as 10,000 men and women by the end of the war – were, as Churchill put it, ‘the geese who laid the golden eggs’ and who, just as importantly, ‘never cackled’. Such was the seriousness with which those at Bletchley took their obligation to silence that many of them refused to speak about what they had done there, even after the existence of Ultra became public knowledge in the early 1970s.