EARLIER this year the administrators of the Metropolitan Museum of Art in Manhattan woke up to a massive institutional headache. A legal letter accused the museum of being implicated in a modern day art heist. It was a charge that brought a new dimension to the old story of colonialism and stolen art.

The Kingdom of Cambodia is pressing for an explanation as to how the Met acquired dozens of Khmer Empire antiquities that Cambodian officials, claim were looted ­during the country’s decades of war.

The accusation is backed by a ­spreadsheet of 45 “highly significant” items that were ­allegedly stolen, before being sold on to the museum. Cambodia’s claims bring the time-honoured story of wealthy and powerful nations acquiring artworks from smaller nations bang up to date.

Since Black Lives Matter swept the globe, claims for arts restitution have soared. The arrival of a high level ­Nigerian delegation, led by President ­Muhammadu Buhari, en route to COP26 in Glasgow has heaped more pressure on the museums’ sector to live up to expectations that looted Nigerian artefacts will be returned.

Those museums and galleries that have benefitted from colonialism and the wholesale theft of valuable cultural artefacts from colonised nations are now ­under intense pressure to ­concede. France will be sending back three ­monumental sculptures, two royal thrones, carved doors, altars and staffs to the West ­African country of Benin in November. The 26 items had been looted by French troops from the city of Abomey in 1892. Not everyone agrees and thus far England and Portugal have been slow to the point of belligerent about returning Benin ­artefacts to Nigeria.

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In Scotland ground has shifted. We have seen a reversal of long standing ­policies at the National Museums ­Scotland based in Edinburgh, which has now adopted “a procedure for considering requests for the permanent transfer of collection ­objects to non-UK claimants”.

The academic community both here and down south have responded better. Aberdeen University was one of the first institutions to return a Benin bronze ­artefact. The head of an Oba (king) to Edo State, Nigeria, which had been looted during the siege of Benin City in 1897. Aberdeen’s decision echoed Kelvingrove Art Gallery’s now historic decision to return an important artefact of Native American culture, the ghost dance shirt, a relic believed to have been worn by a Sioux warrior killed in the 1890 Wounded Knee massacre.

It is the Benin Sculptures that have become the spark-plugs of restitution.

In 1897, British forces razed Benin City, destroyed its palace, and looted its contents as “spoils of war”. More than 1000 bronzes are now displayed in 160 museums and private collections across the world. The bronzes have become ­centrepieces at several western museums and have also been passed down through the legacies of the super-wealthy, the Fords, Rockefellers and de Rothschild families.

But now the moral net is tightening and only the most myopic colonialists still ­argue that they were fairly taken and ­honourably held. The problem is not ­simply colonialism. Many artefacts found their way into museums by ­untrustworthy third parties, hawking old relics for cash, some of them known fraudsters.

A new exhibition space called the Edo Museum of West African Art is set to open in Benin City in 2025, ending once and for all the argument that there is no suitable residency for the bronzes and undermining the conceit that London is their natural home.

You will not be surprised to know that the UK’s ruling Conservative Party are among the most reluctant to return the Benin bronzes. Currently, fantasising that they are part of a post-Brexit “Global Britain’ or more laughably embarking on Empire 2.0, the right-wing charlatans in the loftiest seats in the land are actually proud of Empire and see no reason why stolen loot should be returned.

Westminster favours a “retain and ­explain” policy which explains the origins of an art work, how it came to be here.

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It would be simpler if there was a rule book, about ownership and who has the right to buy or sell valuable artefacts. But that is not the case. The Elgin Marbles, which have been housed at the British Museum in London since the early 19th century, have come under renewed scrutiny since actor George Clooney voiced his support for returning the Marbles to Greece. Meanwhile here at home, the ­status of the Lewis Chessmen rumbles on.

THERE are many lessons for Scotland in this debate. Firstly we are caught in a cultural bifurcation as both hero and villain. Scotland and its people played a brutal role in Empire profiting from the invasion an colonisation of less powerful nations, but we ourselves are a less powerful nation within the Union and need to be more assertive about our own historical artefacts .

Restitution and reparations are areas where I want Scotland to neither hide nor to move in polite unison with England. We need to think and act like and independent nation, owning up to past faults and to the wealth we have extracted from other nations, and be generous in our reparation.

But equally we need to be more assertive about arts from our own past, especially those that can enrich Scotland’s international reputation. The Lewis Chessmen are a thundering case in point.

The Chessmen are a 12th century chess pieces, mainly carved from walrus ivory which were discovered in 1831 on the Isle of Lewis. Of the 93 artefacts found in Uig Bay, 82 are held by the British Museum in London, the remaining 11 in the ­National Museum of Scotland in Edinburgh. Some pieces are still missing unlikely to be found. But six pieces have now found their way home to the new Museum nan Eilean at Lews Castle.

Like the Benin bronzes, the British Museum have resisted returning the full set to Scotland, where they could form the centre-piece for a world class display in Edinburgh. A second scenario would see all the chessmen return and reunited to where they were found on the Isle of Lewis creating an unprecedented tourist attraction and a world centre of medieval society.

A third scenario would be one framed by storytelling. The pieces were ­discovered in sand dunes by one Malcolm McLeod who was cleared from his land by a local landowner. Although ­discovered in ­Scotland, it is possible that the pieces were actually crafted in Iceland by Margert the Adroit the famous ­medieval sculptor. Others claim they chessmen were made in ­Trondheim in Norway by craftsmen working for an ancient king or warrior nobleman, whose longboat was wrecked and the debris washed ashore on the west coast of Lewis.

It’s a story rich in northern drama from medieval warfare to the clearances and one that should be known more widely.

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You may remember that Alex Salmond coined the phrase the “arc of prosperity” describing the group of small independent nations that arch to the north and west of Scotland from Ireland to Denmark. It was often mocked by gloating Unionists, when Ireland and Iceland’s economies shuddered in the heat of the world financial crisis, but Salmond’s argument and the metaphor it gave rise to was right.

The Lewis Chessmen are artefacts that tell the fascinating, under-researched and often disputed story of land and sea that now forms an arch of prosperity around Scotland’s north.

We should host that story not London and we should invited it to travel extensively, on a basis of permanent rotation.

I would even lead a delegation to permanently share the Lewis Chessmen with our friends in Norway if they share their Sovereign Wealth Fund with us.