August 30, 2021

Winston Churchill said that Alan Turing made the single biggest contribution to Allied victory in the war against Nazi Germany.

by Jonathan Schilling

Alan Turing (1912-1954) was a brilliant mathematician and a founder of computer science. He was one of the codebreakers who worked at Bletchley Park during World War II and who played a major role in breaking the cipher systems used on the German Enigma machine thereby generating the Ultra intelligence that proved a key factor in many Allied successes during the war. From at least the mid-1980s on, the claim has been made in various news articles, websites, and a few books that Churchill said that Turing made the single biggest contribution to the Allied victory against Germany.

Churchill was introduced to Turing during a visit to Bletchley Park in September 1941 and the following month Turing and three other cryptographers wrote directly to Churchill asking for more administrative resources, a request which the Prime Minister immediately granted. Undoubtedly Churchill believed Ultra intelligence was of vital importance during the war. However, no documentation has ever been found in which Churchill specifically praises Turing, and the claim does not supply a date or a context in which this statement was supposed to have been made. Certainly, Churchill made no such declaration in public during his lifetime since the existence of Ultra remained fully under wraps until nearly a decade after his death.

While it is not inconceivable that Churchill made such a statement in private conversation, it seems unlikely that he singled out Turing’s role as distinct from the many others who worked on the project. It is unknown whether Churchill still would have remembered who Turing was by the end of the war, or whether he might have been more focused on people higher up on the organizational ladder of generation and distribution of Ultra, such as Bletchley Park directors Alastair Denniston and Edward Travis, or Stewart Menzies, chief of the Secret Intelligence Service/MI6. Thus, unless more information comes to light, we must say there is no evidence to support this claim.