Recognized as the pioneer in IT and artificial intelligence, he committed suicide in 1954, since his homosexuality resulted in a criminal prosecution in 1952 considered un-natural and illegal in the United Kingdom then.
According to Wikipedia, Alan Mathison Turing was an outstanding British mathematician, logician, cryptanalyst and computer scientist, who made noted contribution in development of computer science by providing a formalisation of the concepts of ‘algorithm’ and ‘computation’ with the Turing machine leading to the creation of the modern computer.