New Roman ruler's face on display

The British Museum says the coin shows that Domitianus ruled Britain

A coin that solved the mystery of a Roman emperor is going on display near the field where it was unearthed by an enthusiast with a metal detector.

Brian Malin found the base silver coin, bearing the face of Emperor Domitianus, in a field in Oxfordshire, stuck together in a pot with 5,000 others.

The coin goes on show on Tuesday at Oxford's Ashmolean Museum, after a stay at the British Museum.

It is believed Domitianus ruled Britain for just days after a coup in 271AD.

Historians believe Domitianus was an upstart from the legion, a high-ranking army officer who was ousted for treason for daring to declare himself emperor and having the coins struck.

Domitianus was a high-ranking Roman officer in the 3rd Century AD

Domitianus is thought to have declared himself emperor of the Gallic Empire - a western stretch of the Roman Empire that included Britain, the Rhineland and modern day France.

Only one other coin bearing his face exists, but was dismissed as a hoax until Mr Malin's discovery.

Experts say his discovery proves the earlier coin, found in France 100 years ago, was genuine and that Domitianus did exist.

The fact that he had coins struck in his image shows his bid for power gave him control over a mint, thought to have been at Trier in Germany.

Two ancient texts refer to Domitianus as an officer who was punished for treason under Emperor Aurelian (AD 270-5) - but do not mention that his crime was to seize power himself.

Richard Abdy, the British Museum's curator of Roman coins, said: "The archaeological evidence of this coin shows that he was indeed emperor and provides us with a face to go with history's forgotten ruler."

Mr Malin, who has been searching for treasure with his metal detector for more than 15 years, found the pot of coins in a field 10 miles south-east of Oxford in April 2003, and handed it to the Ashmolean.

The collection, which is valued at £40,000, is dated between 251 to 279 AD and consists of 4,957 Roman coins, spanning five emperors.

The Ashmolean has now purchased the coins with grants from donors including the National Art Collections Fund and the Friends of the Ashmolean.

Visitors can see the collection there until 24 July, when it will be loaned to the Oxfordshire County Museum at Woodstock, during a multi-million pound renovation of the Ashmolean.

When the work is completed, the collection will go on show permanently in the museum's new Money Gallery.