Alan Turing was an English mathematician, who in 1936 published On Computable Numbers , a paper in which he conceived an abstract machine, now called a Turing machine, which moved from one state to another using a precise set of rules, a seminal work in the development of computer sciences and systems theory.
After graduate studies at Princeton University from 1936 to 1938, he worked in the British Foreign Office through World War II, where he played a leading role in efforts to break enemy codes. In 1945 he joined the National Physical Laboratory in London and worked on the Automatic Computing Engine (ACE), where he developed an original detailed design and prospectus for a computer in the modern sense, including a then preposterous 4K of storage space.
In 1948 he became deputy director of the Computing Laboratory at Manchester, where the Manchester University Computer, the first actually running electronic program computer, was being built. He also worked on theories of artificial intelligence, and on the application of mathematical theory to biological phenomenon. In 1952 he began publication of his theoretical study of morphogenesis, the development of pattern and form in living organisms.
Turing was arrested for violation of British homosexuality statutes in 1952, and died of potassium cyanide poisoning during further studies. His work has been invaluable to the further development of complexity theories and computer science, as well as work in articifial intelligence, his legend even permeating the arts with the appearance of his Turing Machines in a recent popular work, "The Diamond Age" by Neal Stephanson.