John Croft, a codebreaker at Bletchley Park during the second world war who later became a successful abstract artist, has died aged 103.
Early life and wartime codebreaking
Croft was studying history at Christ Church, Oxford, in 1942 when his tutor asked if he might be interested in intelligence work. “The prospect, whatever that involved, seemed enticing and I gratefully accepted the opportunity,” he later recalled. He was interviewed by Col John Tiltman, Bletchley Park’s chief codebreaker, and a few months later reported to Bletchley for training alongside other recruits, including the future author Angus Wilson.
He was put to work in the Testery, the section that carried out the initial manual and linguistic process of breaking the German Lorenz enciphered teleprinter system. The Lorenz ciphers, codenamed Fish, were used on the highest security links between Berlin and German fronts, often carrying orders from Adolf Hitler.
Croft recalled that a highlight was “the breaking of a personal message from Hitler demanding the apprehension of the Yugoslav partisan leader General Draza Mihailovic, for which the reward would be ‘a large quantity of gold’”.
Diplomatic and Soviet ciphers
Finding the work sometimes boring, Croft enlisted an aunt’s help to move to Bletchley’s diplomatic and commercial section in Mayfair. He briefly worked on Finnish diplomatic ciphers before being transferred to a new section set up to read messages between Moscow and communist parties across Europe. The section head was mathematician Bernard Scott, who had broken into the messages using a substitution cipher with the Russian alphabet transposed as numbers.
Scott and Croft spent a day searching through editions of Shakespeare’s plays at the British Library for the one used to encipher the key, without success. As Russian armies advanced in 1944, traffic increased, and three more codebreakers were brought in, including Ernst Fetterlein, Tsar Nicholas II’s former official codebreaker.
Kim Philby, then head of a new counter-espionage section inside MI6 dealing with Soviet spies, was a recipient of decoded messages and once visited the section. Shortly after, Fetterlein found his locked cupboard forced open and papers disturbed. Croft believed Philby, later exposed as a Soviet double agent, was responsible.
Post-war career and art
After the war, Croft completed his degree at Oxford but was refused a job at GCHQ. He briefly considered studying art history at the Courtauld Institute, where he was interviewed by Anthony Blunt, later exposed as a Soviet spy. Croft gave the official response about his wartime work, and recalled Blunt was “remote and chilly”.
He studied sociology at LSE and graduated in 1953. After teaching, he joined the Home Office, becoming head of the Home Office Research Unit in 1972, where one colleague was novelist PD James. He retired in 1981 and was appointed CBE in 1982.
While at the Home Office, he took up painting in oils and became a highly regarded abstract artist, focusing on “non-figurative, minimalist work derived from landscape”. His paintings were included in group shows from the 1960s and described by art critic Brian Sewell as “exquisitely judged, hard-edged abstracts”. He had solo exhibitions at the Gardner Arts Centre in 1970 and the University of Warwick in 1971.
Personal life
Born in Brondesbury, north London, to Doris and Oswald Cohen, the family changed their name to Croft in the late 1930s. After living in the Isle of Man, he moved with his partner Ray Kelly to Bath. Kelly died in 1999.
Ivor John Croft, codebreaker, civil servant and artist, born 6 January 1923, died 12 July 2026.
