MANCHESTER: Mathematician Alan Turing, who helped Britain win World War Two with his code-cracking but committed suicide after being convicted for homosexuality, will appear on the Bank of England's next 50-pound banknote, the BoE said on Monday.

"As the father of computer science and artificial intelligence, as well as war hero, Alan Turing's contributions were far-ranging and path-breaking," BoE Governor Mark Carney said. "Turing is a giant on whose shoulders so many now stand."

Turing's electromechanical machine, a forerunner of modern computers, unravelled the "unbreakable" Enigma code used by Nazi Germany. His work at Bletchley Park, Britain's wartime code-breaking centre, was credited with shortening the war and saving thousands of lives.

But he was stripped of his job and chemically castrated with injections of female hormones after being convicted of gross indecency in 1952 for having sex with a man. Homosexual sex was illegal in Britain until 1967.

Turing killed himself in 1954, aged 41, with cyanide. He was granted a rare royal pardon by Queen Elizabeth in 2013 for the criminal conviction that led to his suicide.

As well as an image of Turing, the new note will feature a table and mathematical formulae from a 1936 paper by Turing on computable numbers, an image of a pilot computer and technical drawings for the machines used to break the Enigma code.

The note will also include a quote by Turing 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."

Turing was selected by the BoE from a shortlist of contenders from the fields of science and mathematics, including the late cosmologist Stephen Hawking.

The existing 50-pound banknote features engineer James Watt and his business partner Matthew Boulton, who developed and marketed the steam engine in the late 18th century.

The 50-pound note is the BoE's highest-value banknote and is rarely used in daily transactions. The new note is expected to enter circulation by the end of 2021, the BoE said.