He was educated at Sherbourne School & studied at King's College, Cambridge. A distinguished degree in 1934 followed by a Fellowship of King's College in 1935 and a Smith's Prize in 1936 for work on probability theory, An able and enquiring mind. A bridge between the theortical world and the practical one.
During the 1930s Turing worked on applying mathematical logic to a variety of problems. This resulted in the concept in which a method or algorithm which defined a problem, was separate from a machine which could process the algorithm to produce a solution. By extension, one machine may be used to process several different algorithms. The concept became known as the Universal Turing Machine.
In effect Turing was defining a concept used in a modern digital computers. The algorithm represents a computer program, and the machine is a computer on which many different programs may be run. But he define the concept in the 1930s before the means existed to make such a machine. Mathematition with a practical bent.
During the Second World War, Turing worked on projects that were so secret that they remained secret for the next fifty years. The way forward lay in Turing's generalisation of the Polish Bombe into a far more powerful device, capable of breaking any Enigma message where a small portion of plaintext could be guessed correctly. Turing's brilliant mechanisation of subtle logical deductions.
After the war, Manchester
In 1952, Turing complained to Wilmslow Police about a theft from his house. The investigating officer proved to be more interested in the sleeping arrangements at the house, than the theft. Turing was accused of homosexual acts and charged with gross indecency. The offence was treated more seriously because his partner was 19 years old and thus, in the eyes of UK law at that time, a juvenile. On 31st March 1952 Turing pleaded guilty at Knutsford Quarter Sessions, and was sentenced to chemical castration, by the injection of ....
The conviction made embarrasing headlines in the newspapers. It seriously effected his work because he lost his security clearance. The authorities treated all homosexuals as security risks, a reasonable assumption as the laws against homosexuality created a powerful opportunity for blackmail. The weekly injections of hormones also had their effects.
On 8th June 1954 Eliza Clayton who called daily to do the houskeeping found Alan dead in his bed. He had committed suicide by taking cyanide.
Having helped to create the digital computer, Turing narrowly missed seeing them introduced into commercial use. In the year he died, a Ferranti Mark One Star (Ferranti Mk1*) computer on which he had worked was installed at the nearby Chadderton factory of A V Roe & Co.