British mathematician and cryptographer Alan Turing (1912-1954) is considered the founder of theoretical computer science and the theory of artificial intelligence, the progenitor of modern computing systems. During World War II, the scientist, together with his colleagues, managed to create a device that made it possible to "crack" the code of the German Enigma encoder, an electromechanical rotary machine invented by German electrical engineer Arthur Scherbius in 1918. Thanks to this, the British military could freely decrypt the secret messages of the enemy.Alan Turing's scientific achievements are impressive. The scientist was even recognized as one of the most outstanding thinkers of the XX century. However, behind the success in science there was a personal tragedy.This book tells about the life of Alan Turing and his work at the British Government School of Ciphers and Codes.