RARE silver pennies minted during the reign of William the Conqueror have been unearthed by a metal detector enthusiast in the North Cotswolds.

Kurt Adams, archaeological finds liaison officer for Gloucestershire county council, says the coins are the first of their kind to be discovered and are in perfect condition despite being almost 1,000 years old.

They are causing great interest in the numismatic world as they were made by a minter called Leofwine who had not been known to be minting in Gloucester, he said.

The four pennies have been sent to a coin expert at the Fitzwilliam Museum in Oxford for assessment and will be the subject of a treasure inquest in due course.

Made between 1073 and 1076, the coins are about the size of a 10p and only 0.8mm thick and were found in a field two months ago.

They have a cartoon-like image of William 1 on one side.

The front says 'pillen rex anglo' which means "William King of England" while the reverse says "Leofwine on Glepei" - minted in Gloucester by Leofwine.

Mr Adams said: "There has never been an example of coins of this kind minted by Leofwine in Gloucester before and we had no idea he was in the city doing this at this time."