Sir Arthur Wilfred Bonsall KCMG CBE was born in Middlesbrough in 1917 and most of his childhood was spent in Welwyn Garden City. In 1930 he became a boarder at Bishops Stortford College. He went up to St. Catharines, Cambridge in 1936, getting a degree in French, German and Russian. He then waited a few months for war to break out.
The Army rejected him on health grounds, but Bletchley Park recruited him. He began work there on New Years Day 1940 in the German Air Section which was partly under the control of the Air Ministry. His task was to work on tactical cyphers. During the Dunkirk evacuation he was posted for a few weeks to the RAF intercept station at Cheadle which supplied intelligence to RAF Fighter Command. On return to Bletchley Park he became involved in the production of a potential series of reports containing tactical intelligence about the air war in Western Europe. However, the Air Ministry would not allow these reports to be circulated because they considered it was not Bletchley's function to produce intelligence. It was over a year before they were forced to change their mind. The reports were then produced every day for the rest of the war, the main recipients being the RAF Home Commands and the US VIII Air Force.
In 1941, he married Joan Wingfield who worked in the Italian Naval Section at Bletchley Park. In the final stages of the war he was made Head of the German Air Section.
After the war he joined GCHQ at Eastcote, moving with it to Cheltenham in 1953. He and Joan lived in nearby Stroud and had a large family, four boys and three girls. In 1973, he became Director of GCHQ, retiring in 1978. In recent years he has taken an interest in the fortunes of post-war Bletchley Park, writing an account of the Air Section work he had been involved in. This was entitled 'An Uphill Struggle' and was published by Bletchley Park in their booklet series.