Alan Mathison Turing (1912-1954) was a cryptanalyst and computer scientist who worked at the Bletchley Park code-breaking centre during the Second World War. He devised the machine that worked out the algorithms to which the german enigma machines had been set, so that the allies could decode message ciphers. Without him, its a fair bet to say that Britain would've lost the war.
Turing's homosexuality resulted in a criminal prosecution in 1952 and he was treated with female hormones and chemical castration.
Two years later, Turing died from an allegedly self-administered cyanide overdose in an apple.
Since his death, Turing's heroic status has been recognised in a variety of different capacities, Manchester University named a building after him, and unveiled a statue in memorial of him in Sackville Park off Canal Street. Kings' College Cambridge named their Computer Department after possibly their most valuable alumnus, and there are numerous awards worldwide that are named after Turing. The logo of the 'apple' company (ipods, ipads and macbooks, not Beatles records) is supposed to pay homage to Alan Turing as a pionerring computer scientist, with the bitemark as a nod towards his suicide but the company denies these claims. In 2009, Gordon Brown acknowledged a petition to apologise for the British Government's treating of Turing as a homosexual.