Alan Turing was an English mathematician and pioneer of computer science whose biggest achievement was developing a code-breaking machine known as the Bombe that was used to decipher messages encoded by German machines. This invention is widely thought to have changed the course of World War II and saved countless lives, and Turing is known as the father of artificial intelligence and theoretical computer science.
Turing pioneered the concepts of computation and algorithms with his Turing machine, which is considered by many to be the first general purpose computer. Turing was employed by the British government in its Government Code and Cypher School where he worked on breaking ciphers related to German communications.
Winston Churchill stated that Turing's contribution was the "single biggest" contribution in the war against the Nazis. Military strategists estimate that the development of Turing's machine shortened World War II by up to four years.
Despite his achievements, Turing was prosecuted for homosexuality in 1952 and chemically castrated as punishment. He committed suicide in 1954 at the age of 41 when he ate an apple laced with cyanide. Decades after his death, the queen of England pardoned him for his "crimes" and British Prime Minister Gordon Brown apologized to him publicly on behalf of the British government.