EXPERTS have used ancient DNA analysis to “decode” the secrets of “highly unusual” 14th-century burials in the Scottish Highlands.

A recent project, supported by Historic Environment Scotland, has allowed a fascinating insight into a group of “special” burials excavated in the medieval Church of St Colman at Portmahomack, on Tarbat Ness, Easter Ross at the time of the warring clans.

St Colman’s Church, now the Tarbat Discovery Centre, in Portmahomack was excavated in 1997 by the University of York and FAS Heritage as part of the Tarbat Discovery Programme and 88 burials dating to the 13th to 16th century were revealed.

Central to this group was a burial nicknamed the “six-headed chief” – a man who had died in violent conflict and who was interred in the centre of the nave. He was buried with four extra skulls – belonging to a young woman and three men – set in two pairs to either side of his head.

His grave was later re-opened to bury a second man, displacing the skull of the first, and a while later a third man was buried in a separate grave close by.

The four “extra” skulls and full burials were targeted for detailed scientific research: C14 dating, stable isotope analysis, ancient DNA analysis and facial reconstruction. The results of the C14 dating place the deaths of all the individuals bar one in the late 13th to early 15th century.

The exception was one of the four skulls which dates to the 8th to 10th century and probably belonged to a Pictish monk from the monastic cemetery of that date that lies beneath the Church of St Colman.

Results of ancient DNA analysis undertaken by scientists at the David Reich Lab at Harvard University suggest the full burials and three of the skulls represent several generations of one family.

The two extra male skulls were father and son and, in turn, grandfather and father of the second man to be buried in the grave. The skull of the young woman was the second man’s mother.

Dr Lisa Brown, archaeological science manager at Historic Environment Scotland said: “It is fantastic to see the use of DNA and isotopic analysis helping to provide an insight into the relationships between individuals in a complex multi-person burial. These are techniques that were not available when the excavations first took place.

“We have been delighted to support this project, which, through the application of cutting-edge science, has been able to tell the story of a family group buried in the nave of the church, one that can be presented to the public as part of the work of the Tarbat Discovery Centre”.

In time, the six-headed chief’s son was buried at his side. There are a number of possible family relationships between the two men who shared the grave who are related to one another through the second man’s grandfather.

The contemporary skulls had no doubt been conserved or removed from previous graves and the inclusion of the Pictish skull points to the deliberate inclusion of a prized relic.

The 14th century was a turbulent one seeing war, famine, animal plagues, the Black Death and environmental deterioration. In the face of such challenges, holding and fighting for land territories – an important part of Highland life – would have been even more critical.

Calum Thomson, chairman of the Tarbat Historic Trust, said “this exciting development once again confirms the significance of the Tarbat peninsula to Scotland’s rich and diverse heritage”.