AN Ulster Circle blue plaque was unveiled in Belfast yesterday in honour of a man once praised by Winston Churchill for his code-breaking work.
It was said that the lateral thinking of John Herivel, an ex-pupil at Methodist College, shed light on the way Germans operated the Enigma machine that encrypted military messages.
The plaque was unveiled at his former school yesterday by his daughter, Susan.
Born in August 1918 at Malone Avenue, after leaving school in 1936, Mr Herivel won a scholarship to study mathematics at Sidney Sussex College, Cambridge.
A gifted mathematician, he was tutored by Gordon Welshman, who recruited him to work at Bletchley Park, the top secret home of the World War Two code-breakers
His way of breaking the Enigma ciphers became known as the `Herivel Tip' or Herivelismus.
His simple but amazing breakthrough won him praise by Winston Churchill upon a secret visit to Bletchley.
Welshman wrote that the `Herivel Tip' was a vital part of breaking Enigmas at Bletchley Park.
"If Herivel hadn’t been recruited in 1940, who would have thought of the `Herivel Tip' without which we would have been defeated in May 1940," he said.
"We would have been unable to maintain continuity until the bombs began to arrive many months later. Let there be no misconception about the last point, loss of continuity would, at all stages, have been very serious, if not disastrous.
"Dunkirk took place in May 1940. The British Expeditionary Force snatched victory from the jaws of defeat and the `Herivel Tip' gave us an understanding of what the Germans were planning next."
After the end of the war, Mr Herivel returned to Belfast where he obtained a teaching post at Campbell College.
Later, he moved to become a reader in History and the Science of Philosophy at Queen's University Belfast and then became a Fellow of All Souls College, Oxford.
He passed away suddenly at the age of 92 and was laid to rest in Oxford.
Chris Spurr, chairman of the Ulster History Circle, said: "John Herivel was an insightful mathematician whose intuition discovered a way to break Enigma ciphers by hand.
"His ability in maths was encouraged at Methodist College, and the Ulster History Circle is delighted to commemorate this mathematician and codebreaker with a blue plaque," he said.
"The Circle is particularly grateful to the Ulster-Scots Agency for their financial support towards the plaque, and to Methodist College for their valued assistance."
