Turing, who in 1952 was chemically castrated for a criminal act of 'gross indecency' - engaging in homosexual activities with a 19 year old - has been granted a Royal Pardon by the Queen, absolving him under the Royal Perogative of Mercy.
Known for cracking the infamous Nazi 'Enigma' Code at Bletchley Park, Alan Turing is commonly regarded as helping save thousands of lives with his code-breaking work during World War II. After his conviction for Homosexual acts, as well as his chemical castration, his government security clearance was stripped and Turing was barred from entering the United States. He would go on to commit suicide through cyanide poisoning just two years later.
The Queen's Pardon comes after several years of petitioning by members of the public and the Houses of Parliament - in 2009, then Prime Minister Gordon Brown issued a formal apology on behalf of the British Government for Turing's treatment, but his criminal conviction still stood, until now.
The Royal Perogative of Mercy, a direct absolution of a person's crimes from the head of state, is very rarely issued - excluding Turing's pardon, it has only been invoked three times since 1945, all to absolve people found wrongly accused of murder. Typically, the Royal Perogative is only invoked to absolve someone of crimes they were later found to be innocent of, however the Government chose to make Turing's pardon an exception for his contribution to British science. You can read a full copy of the Queen's pardon here, which comes in effect as of today, December 24th 2013.
Since its introduction as an amendment to the Criminal Law Amendment Act in 1885, to its repeal in 1967, 75,000 British Men were convicted of Homosexual offences. Turing is the only man convicted under the offence to have received a formal pardon.