First-degree incest discovered in genome of ancient Newgrange remains

17 Jun 2020

Aerial view of Newgrange, Co Meath. Image: Ken Williams/

A team led by Trinity College Dublin researchers has found that a member of Ireland’s early ruling elite was born from first-degree incest.

Archaeologists and geneticists have found evidence that the ruling social elite of Ireland some 5,000 years ago were similar to the Inca god-kings and Egyptian pharaohs when it came to keeping it in the family. In a study published to Nature, a team led by researchers at Trinity College Dublin (TCD) found that an adult male buried in the heart of the Newgrange passage tomb was the result of first-degree incest.

Little is known about who was interred in the heart of the 200,000 tonne Irish monument, which is older than the pyramids, or of the Neolithic society that built it more than 5,000 years ago.

“I’d never seen anything like it,” said first author of the paper, Dr Lara Cassidy of TCD.

“We all inherit two copies of the genome, one from our mother and one from our father. Well, this individual’s copies were extremely similar, a tell-tale sign of close inbreeding. In fact, our analyses allowed us to confirm that his parents were first-degree relatives.”

The stond interior chamber of Newgrange.

The interior of Newgrange. Image: Ken Williams/

A powerful extended kin-group

This recent study was part of a survey of ancient Irish genomes that helped unearth a web of distant familial relations between the man discovered in Newgrange and in passage tomb sites across the country, including Carrowmore and Carrowkeel in Co Sligo.

“It seems what we have here is a powerful extended kin-group who had access to elite burial sites in many regions of the island for at least half a millennium,” Cassidy added.

Now universally recognised as taboo and dangerous for the welfare of a potential child, the only confirmed socially accepted examples of incest in the past were seen within a deified royal family. These elites would attempt to intensify hierarchy and legitimise their power by breaking rules about incest, the researchers said.

Prof Dan Bradley, also of TCD, said the location of the man’s skeletal remains is matched by the “unprecedented nature” of his ancient genome. “The prestige of the burial makes this very likely a socially sanctioned union and speaks of a hierarchy so extreme that the only partners worthy of the elite were family members,” he said.

Light shining through the entrance of Newgrange through the solstice chamber.

Image: Ken Williams/

‘Hill of sin’

Another significant discovery helped put some historical context to a local myth around the Newgrange site dating back to the 11th century. The story tells of a builder king who restarted the daily solar cycle by sleeping with his sister.

The Middle Irish place name for the neighbouring Dowth passage tomb, Fertae Chuile, is based on this lore and can be translated as ‘hill of sin’.

The genome survey also unearthed one of the earliest diagnosed cases of Down syndrome in the remains of an infant buried 5,500 years ago in the Poulnabrone portal tomb. Isotope analyses of this infant showed a dietary signature of breastfeeding, suggesting to researchers that the difference was not a barrier to a prestige burial thousands of years ago.

NUI Galway, University College Cork, Sligo IT, the National Monuments Service and the National Museum of Ireland were among the other Irish institutions to work on the study.

Colm Gorey was a senior journalist with Silicon Republic