Dennis William Babbage OBE (26 April 1909 – 9 June 1991) was an English mathematician associated with Magdalene College, Cambridge, and with codebreaking at Bletchley Park during World War II.
[3] During World War II Babbage was the chief cryptanalyst in Hut 6 at Bletchley Park, which decrypted German Army and Air Force Enigma messages.
Babbage and Hugh Alexander were leaders in the Machine Room and in all matters related to the techniques of breaking Enigma keys.
Gordon Welchman who was also in Hut 6 wrote that before the war they were members of a group of geometers known as Professor Baker’s "Tea Party", who met once a week to discuss the areas of research in which we were all interested.
And that I remember his skill on the billiard table, particularly with strokes played behind his back; before the war he had repeatedly beaten me at squash and tennis.