Extract from The PC Pioneers
Alan Turing is famous for his 1936 paper ‘On Computable Numbers’ and for his code-breaking exploits at the Bletchley Park’s Government Code & Cipher School.
Post-war he set out to design a computer the ACE computer at the NPL, but this led to great frustration. He moved to Manchester to join an innovative team and turned his attention more towards software than hardware.
In 1952 he picked up a nineteen-year-old man in the city. The individual, Arnold Murray, later broke into Turing’s home but Turing’s natural response to call the police turned out to be a big mistake. Turing admitted to a sexual relationship at a time when homosexuality was still illegal in the UK. This was also less than a year after Burgess and Maclean defected to the USSR, fanning fears of a linkage between homosexuality and spying. Turing was convicted of indecency, though not of espionage despite concerns over his wartime role. Yet he still lost his security clearance and his consultancy at sites such as GCHQ.
He was offered an alternative to imprisonment and accepted chemical castration. However the oestrogen injections he received resulted in his developing breasts. In 1954 he took his own life by eating an apple filled with cyanide.
In December 2013 the Queen, somewhat controversially, granted Turing a posthumous pardon. In 2015 The film ‘The Imitation Game’ produced a fictional version of his life.