Alan Turing, whose work laid the groundwork for the invention of the modern computer, will be the face of the UK’s new £50 note when it goes into circulation by the end of 2021. Turing will replace Matthew Boulton and James Watt, the pioneers of the steam engine who share the current £50 note, and will join former prime minister Winston Churchill, writer Jane Austen, and artist JMW Turner who are the faces of the new £5, £10, and £20 notes.

Turing has had a complicated relationship with the British government. During World War 2 he lead a team of code breakers to successfully crack the Nazi’s Enigma code and later designed ACE, one of the world’s first stored-program computers. However, in 1952 he was convicted of “gross indecency” for having a relationship with another man and was sentenced to be chemically castrated. The process left him impotent and growing breasts. He later killed himself in 1954. In 2013, he was issued a posthumous pardon by Queen Elizabeth.

“It was nothing short of a tragedy how a country he had served with such distinction treated him after the war, persecuting him for his homosexuality…. That’s why it’s wonderful to see Turing on the note, as a powerful symbol of the long overdue recognition he deserves,” said British AI researcher Demis Hassabis at the unveiling, “The technology we use every day and can’t imagine life without – none of this would have been possible without Turing’s work.”

The Bank of England chose to feature Turing after a public consultation that saw 227,299 submissions that nominated 989 different scientists. To qualify, an individual needed to be real, deceased, and they needed to have contributed to the field of science in the UK. From these nominations, the bank’s advisory committee drew up a shortlist of 12 scientists including physicist Steven Hawking, and Ada Lovelace and Charles Babbage, the latter of which are two earlier computer science pioneers. The final decision of which person to use was made by the governor of the Bank of England Mark Carney.

When the new note is introduced it will complete the UK’s transition to new banknotes that are made out of polymer rather than paper. The new notes are designed to last longer and also include new security features designed to prevent counterfeiting. However, their introduction has also proved controversial due to the use of tallow, an animal byproduct, in their construction.