Dozens of people have been identified as descendants of a Scottish noble family who inscribed their name on the Declaration of Arbroath thanks to a groundbreaking genealogy study at a Scottish university.

A specific genetic group belonging to the Boyd family, which included the Earls of Kilmarnock, was identified as stretching back to around 1205 - 115 years before the document calling on the Pope to recognise Scotland as an independent state was signed.

London-based architect Tim Boyd, a confirmed descendant of constable of Scotland Gilbert Hay and Sir Robert Boyd of Noddsdale, was invited to take a Y-DNA test to create a genetic marker by researchers at Strathclyde University.

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This information was then used to distinguish noble Boyds from others with the same surname by matching the similar genetic strands, helping to identify 30 members of the noble family from as far afield as the United States.

It is the latest part of a project aimed at celebrating the 700th anniversary of the document being signed at Arbroath Abbey. 

Researchers are also seeking the Dunbar, Lindsay, Seton, Sinclair, Stewart and Sutherland families in a bid to bring together distant relatives of the signatories for a special exhibition at the Abbey on July 3.

Hay was made Heritable Constable of Scotland by Robert The Bruce in 1314 following the Battle of Bannockburn.

Sir Robert never held a title, but was an eminent backer of Bruce during the wars of independence.

HeraldScotland: Arbroath Abbey will host a special exhibition with the descendants of the families on July 3Arbroath Abbey will host a special exhibition with the descendants of the families on July 3

Graham Holton, Lead Tutor in Strathclyde’s Genealogy Staff Team, said: “The genetic group we have identified forms part of R-U198 and several more specific genetic markers have also been identified via advanced testing.

“They distinguish this notable family from others of the Boyd surname, some of whom have a very interesting male ancestry of African origin, belonging to another genetic group, A-M32.”

He added: “Around 30 of the members of the Boyd Y-DNA project now know that they belong to the Boyds of Kilmarnock. Scotland is now unfamiliar territory to most of these, since almost all of them live in North America or Ireland, but it remains part of their heritage.”

Mr Boyd was also found to have other notable people in his ancestry, including William Boyd, 4th Earl of Kilmarnock (1705-1746), whose wife was a descendant of Gilbert Hay, and who supported Bonnie Prince Charlie in the 1745 Jacobite rising. 

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After the Battle of Culloden in 1746, in which his son, James, fought on the victorious Government side, the Earl was captured and subsequently beheaded.

James Boyd later became Earl of Erroll and, as a result, took on the name of Hay. 

In 1941, his direct descendant, Josslyn Hay, 22nd Earl of Erroll was the victim of a notorious murder case in Kenya, which became the subject of the 1988 film White Mischief.