The Turing machine
In 1936 Turing described a theoretical machine with an endless tape, a head and a set of rules. He proved that such a simple machine can compute anything that can be computed at all. In this sense every computer today is a Turing machine.
Enigma
During the war Turing worked at Bletchley Park on breaking the German Enigma cipher machine. His electromechanical Bombe machine helped find the daily settings. Historians estimate that the codebreaking shortened the war by years.
A tragic end
In 1952 Turing was convicted of homosexuality, which was a crime in Britain at the time, and underwent forced hormone treatment. He died in 1954. The British government apologised in 2009, and in 2013 the Queen granted him a pardon. Since 2021 he has appeared on the British £50 note.
The test today
Modern language models routinely pass the Turing test in short conversations. It turns out the test measures the ability to imitate a human rather than real understanding.