Alan was a really good mathematician and code breaker.
He worked at Bletchley Park with a team of other code breakers to try and crack the supposedly unbreakable code Enigma. Enigma was a machine that the Germans could send messages via but they were all in code so their enemies could not break it. There were many possibilities and they needed something that could break the code. So Turing invented the first computer to break the code. The work they did is believed to have shorted the war by about two years!
The Team At Bletchly Park
There were a few different people that worked with him called cryptographers. The only woman that worked with him was called Joan Clarke and this is because in those times people were very sexist and thought women should not be working with them. They became very close friends because they were both thought of as outsiders, had similar passions and got on very well together. Turing and Joan later got engaged but it was very short-lived and was later called off.
In 1952 he was arrested and then tried for homosexuality which was then at the time illegal. Instead of going to prison he agreed to have a drug called oestrogen which he was injected with for a year. The drug was supposed to make him ‘normal’. They also thought he would be a security risk so he was stopped from working at the GCHQ which was where he worked before Bletchley Park.
He studied maths at Cambridge University and also taught there.