military messages was of inestimable help to the Allies in winning the war. It was achieved largely because of the efforts of Twinn, Knox, Alan Turing (who later became the father of artificial intelligence) and others at Bletchley Park. Turing, a brilliant mathematician, developed a machine called the “bombe”, which speeded up the deciphering process by trial and error — a crucial development for the codebreakers. German Naval Enigma Twinn worked with Turing on breaking the German Naval Enigma. Their success helped allied convoys to avoid German U-boats. Intelligence Services Knox In October 1941, Dilly Knox solved the Abwehr Enigma. Intelligence Services Knox (ISK) was established to decrypt Abwehr communications. In early 1942, with Knox seriously ill, Twinn took change of running ISK and was appointed head after Knox's death. By the end of the war, ISK had decrypted and disseminated 140,800 messages. Intelligence gained from these Abwehr decrypts played an important part in ensuring the success of Double-Cross operations by MI5 and M16, and in Operation Fortitude, the Allied campaign to deceive the Germans about D-Day. Post-war career Twinn's carried on government work after the war in a number of departments, including, in the late 1960s, as Director of Hovercraft in the Ministry for Technology. Later he became Secretary of the Royal Aircraft Establishment in Farnborough. In the early 1970s, he was the second secretary of the Natural Environment Research Council. He was appointed CBE in the 1980 Birthday Honours. Twinn became interested in entomology, gaining his doctorate from the University of London in the jumping mechanism of click beetles. He co-authored A Provisional Atlas of the Longhorn Beetle (Coleoptera Cerambycidae) (1999), a study of the distribution of a number of beetle species. Twinn had an interest in music and played the clarinet and viola. Twinn married Rosamund Case, whom he had met at Bletchley Park through his interest in music, in 1944; they had a son and three daughters. Publications Peter F. G. Twinn and P. T. Harding, "Provisional atlas of the longhorn beetles (Coleoptera, Cerambycidae) of Britain", Huntingdon: Biological Records Centre, 1999. Notes References External links Telegraph obituary 1916 births 2004 deaths People educated at Dulwich College Bletchley Park people English entomologists Alumni of Brasenose College, Oxford Alumni of the University of London Commanders of the Order of the British Empire People educated at Manchester Grammar School 20th-century British zoologists