Who Was Alan Turing? And Why Did Queen Elizabeth Grant Him a Pardon? Alan Turing, the British mathematician who helped defeat the Nazis by cracking their secret codes and laid the groundwork for modern computer science, was posthumously pardoned by Queen Elizabeth on Monday for a 1952 conviction for being gay. Here's what you need to know about Turing. Alan Turing Born: June 23, 1912 Died: June 7, 1954, at age 41. Turning killed himself, likely by eating an apple poisoned with cyanide, following a criminal conviction for homosexuality. Accomplishments: Turing is widely considered the father of computer science. His developments in cryptography were instrumental in cracking the Nazi's Enigma code, a vital step in turning World War II in favor of the allies. Turing predicted the rise of computers and essentially invented the idea of software. He was first to define artificial intelligence and design a test to determine whether computers could truly appear to be human. Controversy: Despite his contributions to the war effort and to science, Turning was charged with "gross indecency" in 1954, under laws that at the time criminalized homosexuality. Rather than serve prison time, Turning agreed to a form of chemical castration, in which he was injected with female sex hormones. Later that year he killed himself. Legacy: Every computer today, from cells phones to those aboard the International Space Station, owe their existence to the "Turing Machine," the first modern computer to run interchangeable software. As computers become smarter and seemingly more human, the "Turing Test," an experiment in which human subjects must determine if they are interacting with another person or a computer, remains the standard by which artificial intelligence is measured. Turing's life has been commemorated in books, a monument, a play and an upcoming feature film. His action saved countless lives. He also left a remarkable national legacy through his substantial scientific achievements, often being referred to as the "father of modern computing,"" British Prime Minister David Cameron said in a statement.