Alan Turing (1912-1954) was an English mathematician who contributed enormously to very foundations of our modern computer-driven world. Although many people have heard of his involvement in breaking the German “Enigma” code during WWII, his life before and after this period is equally important. In the 1930s, he conceived of the Turing Machine, a hypothetical computational device critical to solving mathematic’s “decision problem”. After the war, he worked with some of the earliest electronic computers and after turning to the problems artificial intelligence, concocted the Turing Test, a means of verifying computer intelligence. Turing’s life story would be incomplete without noting his homosexuality, acts of which were illegal in the U.K. in his lifetime. A conviction of gross indecency in 1952 led to chemical castration, loss of his security clearance, and eventually, his death by an apparent suicide in 1954. Turing’s theories and efforts have led to his wide recognition as a father of computer science, without whom our modern world might be very different.