On 24 December 2013, Alan Turing was granted a posthumous pardon by Queen Elizabeth II under the Royal Prerogative of Mercy, following a request from Justice Secretary Chris Grayling. The official UK government announcement on gov.uk called Turing “an exceptional man with a brilliant mind” and described his 1952 conviction for homosexual activity, and the chemical castration that followed, as “a sentence we would now consider unjust and discriminatory and which has now been repealed.”
Turing had been pivotal to breaking the Enigma code at Bletchley Park during the Second World War. In 1952 he was convicted of gross indecency, lost his security clearance, and was subjected to hormone treatment; he died in 1954 in what was ruled a suicide. The pardon was unusual: such pardons are normally reserved for the demonstrably innocent and requested by a family member, but in Turing’s case the government issued one without either condition being met, “reflecting the exceptional nature of Alan Turing’s achievements.”
The pardon followed a 2009 public apology by Prime Minister Gordon Brown for the “appalling” treatment Turing received. It later led to the 2017 “Turing law,” which posthumously pardoned thousands of other men convicted under the same now-repealed laws. For a field that traces much of its conceptual foundation to Turing’s 1936 and 1950 papers, the pardon is a reminder that one of its founders was prosecuted by his own government for who he was.