Blog Image

Happy Birthday Alan Turing!

Today marks the birthday of Alan Turing, a legendary mathematician. It is also pride month and there is a new £50 note out today. Read on to see how these are all related in the life and legend of Turing.


Alan Turing (born June 23rd 1912, died June 7 1954) was a British mathematician and logician. His work laid the foundations for developments in computer science and artificial intelligence. 

Turing was accepted at King’s College, Cambridge and was made a ‘fellow’ when he was only 23. He then gained a doctorate at Princeton University in 1938 and came back to work at Cambridge University.

World War II

In World War II the Germans had developed a seemingly unbreakable ‘Enigma’ code which made their underwater movements hard to track. Britain’s Government Code and Cypher School (now known as GCHQ) at Bletchley Park in London, recruited Turing to help decipher this code. He successfully led a team to develop a huge machine called the ‘Bombe’ to break the code and enable allied ships to change their course without fear of detection. This made the secret ‘Normandy’ landings possible, thus defeating the Germans and stopping the war short in 1945.

Post World War II

After WWII Turing worked on a ‘Universal Turing Machine’, this was the start of what we know now as Artificial Intelligence. The machine allowed something mechanical to be programmed to perform set tasks by the human mind. In 1950 he wrote about the ‘Turing test’, which was an experiment that tested a machine’s ability to mimic human intelligence. His fascination with the relationship between human thought and automated processes laid the foundations for the development of computers and AI.

The tragedy

Alan Turing died at just 41 years old, in 1954. It is said that he commited suicide by cyanide due to issues connected to his homosexuality. In 1952, a time when homosexuality was a crime in Britain, he was convicted of ‘gross indecency’ over his relationship with a man. Turing was ridiculed and subject to humiliation, taking away from the genius he was. He was sentenced to 12 months of hormone ‘therapy’ and also banned from further work with the GCHQ. 

Activists and scientists campaigned for a pardon for him, after homosexuality was ‘decriminalised’ in 1967. In 2009 the British Government issued a formal apology and in 2013 the Queen granted him a posthumous royal pardon. In 2014 his life was portrayed through the film ‘The Imitation Game’, starring Keira Knightley and Benedict Cumberbactch. 

The new £50 note

The process of deciding who would be on the new note began in 2018 with the Bank of England asking the public for their views on who it should be. Over 225,000 names were put forward and Turing was one of 989 scientists nominated. There was a shortlist of 12 and Mark Carney, the Bank’s Governor at the time, chose Mr Turing. 

The new note features a picture of Turing that was taken by Elliot & Fry in 1951. It sits alongside a table of a mathematical formula from his 1936 paper which laid the groundwork for modern computer science. Below the picture is an important quote from him: “This is only a foretaste of what is to come, and only the shadow of what is going to be”. 

The Bank’s now Governor, Andrew Bailey has said, “By placing him on our new polymer £50 banknote we are celebrating his achievements, and the values he symbolises’. 

The director of the GCHQ Jeremy Fleming said “Turing was embraced for his brilliance and persecuted for being gay…His legacy is a reminder of the value of embracing all aspects of diversity, but also the work we still need to do to become truly inclusive.”

Today, Turing is celebrated as one of the most influential and brilliant minds of all time.


  1. Barber, Lindsey & Borland, Hollie. Notable People. New £50 note with Alan Turing: release date and who’s on it explained. 2021
  2. Kumar, Anu. The man and his machine. 2021
  3. Copeland, B. Alan Turing: British mathematician and logician. 2021
  4. Sky News

  • Written by Mikita Maru, June 23 2021