LONDON — His code-breaking skills helped the Allies outfox the Nazis, his theories laid the foundation for the computer age, and his work on artificial intelligence still informs the debate over whether machines can think.
But Alan Turing was gay, and 1950s Britain punished the mathematician's sexuality: He faced a criminal conviction, intrusive surveillance and hormone treatment meant to extinguish his sex drive.
Now, nearly half a century after the war hero's suicide, Queen Elizabeth II has finally granted Turing a pardon.
"Turing was an exceptional man with a brilliant mind," Justice Secretary Chris Grayling said in a statement released today. Describing Turing's treatment as unjust, Grayling said the code breaker "deserves to be remembered and recognized for his fantastic contribution to the war effort and his legacy to science."
The pardon has been a long time coming.
Turing's contributions to science spanned several disciplines, but he's perhaps best remembered as the architect of the effort to crack the Enigma code, the cypher used by Nazi Germany to secure its military communications.
"It could be argued and it has been argued that he shortened the war, and that possibly without him the Allies might not have won the war," said David Leavitt, the author of a book on Turing's life and work.
Even before the war, Turing was formulating ideas that would underpin modern computing, ideas which matured into a fascination with artificial intelligence and the notion that machines would someday challenge the minds of man. When the war ended, Turing went to work programing some of the world's first computers.
Turing made no secret of his sexuality, and being gay could easily lead to prosecution in post-war Britain. In 1952, he was convicted of "gross indecency" over his relationship with another man, and he was stripped of his security clearance, subjected to monitoring by British authorities and forced to take estrogen to neutralize his sex drive — a process described by some as chemical castration.
Depressed and angry, Turing committed suicide in 1954.