A medieval chess piece missing for almost 200 years could fetch STG1 million ($A1.82 million) at auction after a family discovered the object they kept in a drawer is one of the long-lost Lewis Chessmen.
The Lewis Chessmen - a famous hoard of 93 objects - were discovered in 1831 on the Isle of Lewis in the Outer Hebrides.
But the whereabouts of five pieces from the collection have remained a mystery.
A family has now been told the chess piece their grandfather bought for just STG5 in 1964 is one of the missing treasures.
The antiques dealer, from Edinburgh, had no idea of the significance of the 8.8cm piece, made from walrus ivory, which he passed down to his family.
They have looked after it for 50 years without realising its importance, before bringing it to Sotheby's auction house in London where it will go up for auction on July 2 with an estimate of STG600,000 to STG1 million.
The Lewis Chessmen are among the biggest draws at the British Museum and the National Museum of Scotland in Edinburgh.
They are seen as an "important symbol of European civilisation" and have also seeped into popular culture, inspiring everything from children's show Noggin The Nog to part of the plot in Harry Potter And The Philosopher's Stone.
Sotheby's expert Alexander Kader, who examined the piece for the family, said that his "jaw dropped" when he realised what they had in their possession.
"They brought it in for assessment. That happens everyday. Our doors are open for free valuations," he told the Press Association.
"We get called down to the counter and have no idea what we are going to see. More often than not, it's not worth very much," the auction house's co-worldwide head of European sculpture and works of art, said.
"I said, 'Oh my goodness, it's one of the Lewis Chessmen'.
"It's a little bit bashed up. It has lost its left eye. But that kind of weather-beaten, weary warrior added to its charm," he said.
Despite not knowing its significance, the late 12th/early 13th century chess piece had been "treasured" by the family.
Some 82 Lewis Chessman pieces are in the British Museum and 11 pieces are held by the National Museum of Scotland.
Since the hoard was uncovered in 1831, one knight and four warders have been missing from the four combined chess sets.
The newly discovered piece is a warder, a man with helmet, shield and sword and the equivalent of a rook on a modern chess board, which "has immense character and power".
It is thought the horde was buried, possibly by a merchant to avoid taxes after being shipwrecked, shortly after the objects were made and so remained underground for 500 years.
The object will go on display in Edinburgh on Tuesday and in London just before the auction, with Kader saying it could be bought by or be loaned to a museum.
