AN historic royal ring will attract keen bidding when it dazzles would-be buyers at Tavistock auctioneer Robin Fenner's next sale.

The 16th century miniature portrait ring, set in gold and surrounded in rubies and seed pearls, encloses a 1546 portrait of the young Mary Queen of Scots. It is believed to have been painted on her fourth birthday.

Mr Fenner said: 'We are delighted to have been instructed to offer this important and unique item. It has been consigned to sale by a gentleman living on Dartmoor.'

Mr Fenner originally estimated bidding would reach between £3,000 to £5,000. But he now believes, because of escalating interest, the final figure will 'travel on' when it falls before the gavel on March 11.

Mary, the daughter of James V of Scotland, was born at Linlithgow on December 8, 1542. She became the youngest monarch ever when her father died six days after her birth.

Mr Fenner understands the unique ring was given to a Mary Strickland by Mary shortly before her execution in February, 1587.

The ring, bearing indistinct lettering, has remained in a branch of the Strickland family ever since. It is just under three-quarters of an inch in diameter — which includes the surround.

The present owner's mother was a Strickland through marriage, and the last of this particular Strickland lineage.

Mr Fenner said this was the earliest piece of British art he had ever handled in terms of uniqueness and historic interest.

'It is not a major work of art — it is the historic significance that makes the item so exciting. It is a tremendous piece of British monarchy.'

Over the years the glazing has crazed making the date difficult to see.

'But when I took it outdoors to photograph it a shaft of sunlight just hit the angle — and there it was!' said Mr Fenner.

'We have enjoyed the privilege of offering a fine run of historic items in recent months.

'This amazing little piece of British history follows rapidly on the heels of the cache of Charles Dickens letters and the artefacts relating to the Antarctic expedition of Robert Falcon Scott,' said Mr Fenner.