Arthur Bonsall

Sir Arthur Wilfred (Bill) Bonsall KCMG CBE (born 25 June 1917) is a former director of the British signals intelligence agency, GCHQ, a post he held from 1973 to 1978.

Career

Educated at Bishop's Stortford College, Bonsall went on to study modern languages at St Catharine's College, Cambridge before joining the Government Code and Cypher School at Bletchley Park.

From 1940 Bonsall served in the German Air Section under Josh Cooper, studying the Luftwaffe. In 1942 he helped to create a series of daily reports known as the BMP (from the initials of its three co-creators, Bonsall, Moyes and Prior). They were based primarily on Luftwaffe radio-telephony and low-grade codes and were issued at Secret Pearl level. Later reports included information from Luftwaffe Enigma traffic and were issued at Top Secret Ultra level. They dealt with the operations of the Luftwaffe defensive organisation and assisted the Allied Air Commands to design their tactics.

Bonsall stayed on with the organisation, which became GCHQ after the war, and served as its director from December 1973 to 1978. He was knighted in 1977. He has rarely spoken or written of his work at Bletchley Park though did present a paper in 2007 to a research group in Oxford entitled Bletchley Park and the RAF Y Service, some recollections.

In September 2013 he gave an interview about his career to the BBC.