OXFORD was the birthplace of the popular myth of King Arthur, new research has shown.

The first recorded version of the life of King Arthur was by Geoffrey of Monmouth in his Historia Regum Brittaniae – the History of the Kings of Britain.

And a leading Arthurian academic has now confirmed the stories were written at the part of Oxford Castle which was used as St George’s Chapel in the 12th century, the crypts of which are still standing.

Prof Helen Fulton, professor of medieval literature at York University, a graduate of Oxford University’s Linacre College, said the location of the chapel and evidence of when Geoffrey was based there as a canon between 1129 and 1151 indicated he wrote the historical piece there.

She said: “It’s exciting to discover a new piece of the jigsaw in the quest to trace the origins of the Arthurian legends.

“We know he must have been in Oxford in at least 1129 or earlier and the book was written around 1136.

“There isn’t much Arthurian material around in Oxford or evidence associating Oxford with Arthurian legend, but Geoffrey was the first person to write down an extended bibliography of King Arthur – he put forward a life story from birth to death.”

Prof Fulton said it was “almost certain” Geoffrey was based at the chapel .

She added: “Geoffrey can certainly be traced to Oxford between 1129 and 1151 because his name appears as a witness on a number of charters – grants of land normally awarded by the king to a particular priory.

“One was the foundation charter for Osney Priory and he had a close connection with the canons of St George in Oxford.

“His life of Merlin was dedicated to one of the canons of St George.”

Oxford Castle’s Ellie Stokes approached Prof Fulton for confirmation after looking at the dates of charters in the Oxford area on which Geoffrey of Monmouth’s name appears.

She said: “Since working at the castle, I had been told it was the case but it had never been confirmed by an expert.

“It was always treated as rumour rather than fact, which is why I took the opportunity to research further.”

While Geoffrey of Monmouth is a ‘character’ within the visitor attraction, following the revelation of the Arthurian link a new tour guide dressed as Geoffrey will be making regular appearances.

Castle duty manager Joseph Hartshorn is among those who will be guiding visitors.

He said: “Oxford is getting very interesting. It’s not all about universities, all kinds of things happened here and it’s nice to bring another layer.”

Oxford Castle Unlocked is running an event called King of the Castle from May 25.

Geoffrey of Monmouth facts

Geoffrey of Monmouth was a 12th-century cleric and writer who was a key figure in the legends of King Arthur.
Relatively little is known about his life but it is believed he was born around 1100 in Wales or the Welsh Marches and had a Breton father and a Welsh mother.
He is described as magister, a Latin word meaning master, which suggests he may have been teaching in the early days of the university.
Geoffrey did not create the Arthurian myth but he was the first person to write down an extended life story of the legendary king.
Although he did not produce accurate historical works Geoffrey remains an important figure as a creator of literary legends.
He was made bishop of St Asaph in 1152 and died in 1155.