The Bank of England has unveiled the new £50 banknote, which celebrates the achievements of mathematician Alan Turing.
Mr Turing was a British mathematician who helped Britain win World War Two with his code-breaking skills and he was also known for his work on what would later become computer science.
Sarah John, chief cashier at the Bank of England told Sky News: “He’s best known for his code-breaking work… but beyond that he’s known as the father of computer science.
“He envisaged the basics of what we’ve come to know as the modern computer and the impact that has had on our everyday lives, that legacy, has been absolutely enormous.”
Ms John said the process for deciding who would feature on the note began back in 2018 when the Bank asked members of the public for their views.
More than 225,000 names were put forward and Mr Turing was one of 989 individual scientists nominated.
A shortlist of 12 was produced and the Bank’s governor at the time, Mark Carney, chose Mr Turing.
The note features an image of the scientist, mathematical formulae from a 1936 paper he wrote that laid the groundwork for modern computer science, and technical drawings for the machines used to decipher the Enigma code.
It also features one of his quotes about the rise of machine intelligence: “This is only a foretaste of what is to come, and only the shadow of what is going to be.”
The note will be released for public use on 23 June this year, which coincides with the day Mr Turing was born in 1912.
Its security features include two windows and two-colour foil which, like the £20, are intended to make it difficult to counterfeit.
There is also a hologram image which changes between the words ‘Fifty’ and ‘Pounds’ when tilting the note from side to side.
The polymer £50 note will join the Churchill £5, the Austen £10 and the Turner £20, meaning all Bank of England banknotes are now available in polymer.
Current £50 notes can continue to be used and the BoE will give at least six months’ notice of the date when they will be withdrawn.
The Bank’s governor Andrew Bailey said: “There’s something of the character of a nation in its money, and we are right to consider and celebrate the people on our banknotes, so I’m delighted that our new £50 features one of Britain’s most important scientists, Alan Turing.
“Turing is best known for his codebreaking work at Bletchley Park, which helped end the Second World War.
“However in addition he was a leading mathematician, developmental biologist, and a pioneer in the field of computer science. He was also gay, and was treated appallingly as a result.”
Mr Turing was convicted of “gross indecency” in 1952 at a time when homosexuality was a crime in Britain, and he was sentenced to 12 months of hormone “therapy”.
The conviction meant he could never again work for Government Communications Headquarters (GCHQ), the British government’s postwar code-breaking centre.
An inquest attributed his 1954 death to suicide.
In 2009, Gordon Brown, who was prime minister at the time, publicly apologised on behalf of the government for Mr Turing’s “utterly unfair” treatment.
Four years later, the Queen granted him a royal pardon.
Mr Bailey said on Thursday: “By placing him on our new polymer £50 banknote, we are celebrating his achievements, and the values he symbolises”.