Calls have been made for the pieces to be returned to Lewis
New research has cast doubt on traditional theories about the historic Lewis Chessmen.
The 93 pieces - currently split between museums in Edinburgh and London - were discovered on Lewis in 1831.
But the research suggests they may have been used in both chess and Hnefatafl - a similar game that was popular in medieval Scandinavia.
It also casts doubt on the traditional theory that the ivory pieces were lost or buried by a merchant.
The research was led by Dr David Caldwell of the National Museum of Scotland, who believes the Lewis chessmen were more likely to have belonged to a high-ranking person who lived on Lewis.
Dr Caldwell told the BBC's Good Morning Scotland programme that many of the pieces could have doubled for Hnefatafl, another conflict game which also pitted a king against pawns or warriors on the other side.
The ancient game has not survived into modern times.
For the first time, they also tried to work out which pieces were made by the same groups of craftsmen by measuring the chessmen's faces, looking at their clothing, and studying details of the workmanship.
Dr Caldwell added: "We certainly still believe the pieces are Scandinavian in origin, perhaps made in a workshop by several masters in a city like Trondheim.
"But one of the main things I think we are saying in our research is that it is much more likely that the horde is in Lewis because it belonged to somebody who lived there rather than being abandoned by a merchant who was passing through.
"To take a relatively easy example, there is a praise poem written in the middle of the 13th century to Angus Mor of Isla, and the poem says that he inherited his ivory chess pieces from his father Donald - that makes Angus the very first Macdonald, and the poem also makes him the king of Lewis.
"Now you of course you would be foolish to implicitly believe everything in a praise poem, but nevertheless it gives you some idea that we are dealing with a society in the west of Scotland - great leaders like Angus Mor, bishops, clan chiefs - who really valued playing chess and saw it as being one of their accomplishments."
He said that the analysis tried to recognise the work of different craftsmen, and home in on pieces which may be replacements for ones which had been broken or lost.
They used a forensic anthropologist, Caroline Wilkinson based at Dundee University, to do a photogrammetric analysis of the faces as they believed individual craftsmen would have given their faces different characteristics, just like a modern-day political cartoonists.
Plenty of mystery
Dr Caldwell said the chessmen suggested that there was a reasonable amount of wealth in the western Isles in the 13th century, perhaps because the medieval economy placed greater value on fairly barren land that could be used to raise cattle.
He added: "It was certainly leading men there, people who could make a lot of money either by raising cattle or frankly by going raiding - there was still in some ways a Viking way of life surviving into the 13th century."
Despite the extensive research, Dr Caldwell said he still believed there was plenty of mystery surrounding the chessmen.
"I would be very disappointed if we have written the last word on the - what I hope we have done is opened up the debate and shown it is possible, even with something very well known, to discover new things," he said.
The research will be published this week in the journal Medieval Archaeology.
Of the 93 pieces found, 82 are kept at the British Museum, with 11 held by the National Museum of Scotland.
Calls have been made for all of the pieces, which were made from walrus ivory and whales' teeth, to be returned to Lewis.