A ground breaking DNA study has found that half of all the men who carry the surnames Stewart, or Stuart, are descended from Scotland’s royal dynasty.
The same investigation has also traced, for the first time, the rise of a male DNA lineage to a single individual in the 13th century who founded a branch of the Royal Stewart line.
There are about 70,000 people with the surname in Britain, and the findings mean that around 17,500 men, regardless of their family trees, can now claim to be of royal descent.
Sir John Stewart of Bonkyll died in 1298 fighting alongside William Wallace at the Battle of Falkirk, but his well-documented pedigree allowed ScotlandsDNA to carry out tests on his descendants, and those of his brother James, the 5th High Steward of Scotland and the grandfather of Robert II, the first Stewart king.
Dr Jim Wilson, the group’s chief scientist, carried out ancestry tests on the descendants of Sir John’s sons Richard and Angus, and of his brother, and discovered a marker that originated more than 700 years ago.
He said the exciting discovery was made possible by the remarkable pedigree of the Stewart family.
The results show that that the modern descendants of both sons of Sir John carry a Y chromosome marker S781+ that is absent in the descendants of James.
Dr Wilson added: “By a straightforward process of deduction that means that the marker arose in Sir John Stewart of Bonkyll, and not in his father. If it had, the descendants of James would also carry it, and they do not.” Having made the discovery, ScotlandsDNA checked its database of ancestry tests for men with the Stewart surname and found that 20 per cent of them share Sir John’s lineage, while 30 per cent are descended from his brother James.
James’s son Walter, married Marjorie Bruce, the daughter of Robert I, having helped him win the great victory at Bannockburn, and their son became Robert II.
Alistair Moffat, co-founder of ScotlandsDNA, added: “In the year of the 700th anniversary of Bannockburn, thousands of Scottish men can claim to be directly descended from the Stewarts who fought alongside Bruce, and they can directly identify with generations of famous figures who shaped Scotland and Britain.” The Duke of Buccleuch, Scotland’s biggest private landowner, who is directly descended from Sir John, and a long line of Scottish and British kings, said he was fascinated by the DNA detective work.
He added: “My family’s history has always been closely involved with the history of Scotland and Britain, but the fact that the rise of a DNA marker has been identified in an individual brings the past even closer, and makes it more personal.
“I am delighted to have been a guinea pig for the sort of history it is now possible to write thanks to DNA research.” The sampling has also, for the first time, distinguished clearly between different cadet branches of the royal Stewarts.
The four branches are the Appin Stewarts who fought at Culloden, the Lennox Stewarts who were direct ancestors of James VI and I, and the Albany and Moray Stewarts who acted as regents.