Scientist, Cryptographer, Mathematician, Logican, Philosopher. During World War II, he was instrumental in contributing to decipher the Nazi code. Some sources say this work was decisive for defeating the Third Reich. He was born in Paddington, West London, England. His father, Julius Mathison Turing, was a member of the Indian Civil Service. Very early in life, he showed signs of the genius he was to display more prominently later, presenting an early affinity for numbers and puzzles. He attended St. Michael's, a day school, at six years of age. The headmistress recognized his genius early on, as did many of his subsequent educators. In 1926, at the age of 14, he went to Sherborne School in Dorset. His first day of term coincided with a general strike in England, and, so determined was he to attend his first day, that he rode his bike unaccompanied over sixty miles from Southampton to school, stopping overnight at an inn - a feat reported in the local press. Turing's natural inclination toward mathematics and science did not earn him respect with the teachers at Sherborne, a famous and expensive public school (a British private school with charitable status), whose definition of education placed more emphasis on the classics. He demonstrated remarkable ability in the studies he loved, solving advanced problems in 1927 without having even studied elementary calculus. In 1928, at age sixteen, he encountered Albert Einstein's work. Not only did he grasp it, but he extrapolated Einstein's questioning of Newton's laws of motion from a text in which this was never made explicit. He then attended King's College, Cambridge, where he was an undergraduate from 1931 to 1934, graduating with a distinguished degree. In 1935, he was elected a Fellow at King's College. During World War II, Turing was a major participant in the efforts at Bletchley Park to break German ciphers. His code-breaking work was kept secret until the 1970s; not even his close friends knew about it. He contributed several mathematical insights into breaking both the Enigma machine and the Lorenz SZ 40/42 (a teletype cipher attachment), the code by means of which the German Armed Forces sought to protect their radio communications; and was, for a time, head of Hut 8, the section at Bletchley Park responsible for reading German Naval signals. To break Enigma, he devised an electro-mechanical machine which searched for the correct setting of the Enigma rotors. The machine was called the bombe, named after the Polish-designed bomba. Using a bombe, it was possible to ignore the effect of the Enigma plugboard and consider the settings of its rotors alone, thus eliminating most of them from consideration for each possible setting. A chain of logical deductions was implemented electrically, and it was possible to detect when a contradiction had occurred and rule out that setting. Over 200 hundred bombes were in operation by the end of the war. In 1940, Turing solved the Naval Enigma system, which was more complex than the indicator systems used by the other services. Thanks to bombes, by early 1942, Bletchley Park was decoding about 39,000 intercepted messages each month, rising subsequently to over 84,000 messages a month. Turing's work on the version of Enigma used by the German Navy was vital to the battle for supremacy in the North Atlantic. He also contributed to the attack on the cyphers known as " Fish." Based on binary teleprinter code, Fish was used during the latter part of the war in preference to Morse-based Enigma for the high-level signals, such as messages from Hitler and members of the German High Command. It is estimated that the work of Bletchley Park shortened the war in Europe by at least two years. Turing received the Order of the British Empire for the part he played. He became involved in discussions on the contrasts and similarities between machine and brains. Turing's view expressed, with great force and wit, an unbridgeable gap between the two, stating just where the difference lay. In 1950, he published computing machinery and intelligence in Mind. It is another remarkable work from his brilliantly-inventive mind which seemed to foresee the questions which would arise as computers developed. He studied problems which today lie at the heart of artificial intelligence. It was in this 1950 paper that he proposed the Turing Test which is still today the test people apply in attempting to answer whether a computer can be intelligent. In 2002, a BBC popular poll placed Turing as the 21st Great Britain of all time. Alan Turing died in 1954; the inquest found he had committed suicide by eating an apple laced with cyanide. He was cremated at Woking, Surrey, England.