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Recreated Viking helmet and weapon

Vikings in Ireland: Traces of Warriors Not Just Buried Beneath the Ground, They Are in the DNA

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As science progresses and archaeologists are forging new positive relationships with developers around Irish heritage, more secrets from Ireland’s Viking past are coming to light, and they are not just found in burial grounds, unearthed dwellings, and old settlements; they can be found in the DNA of the modern-day Irish people. The Vikings may have only been present in Ireland for three centuries – a drop in the ocean compared to its long and dramatic history – but recent research is showing that their influence was far greater than previously realised.

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Recent Research Shows Viking Influence Has Been Heavily Underestimated

It has long been known that the Vikings – in Ireland’s case, the Norse and the Danes – eventually settled down and lived alongside the Irish clans, in some cases intermarrying and allying themselves with Irish chieftains.

“As early as the middle of the ninth century we hear of a mixed race called the Gall-Gael (Gaill-Gaedhil) of partly Scandinavian and partly Irish blood, who began to collect formidable armies. Intermarriage and settlement must thus have been frequent at a date when it is customary to think of the Norse as mere occasional raiders along the coasts.” (Hull, 1931).

Sea-faring Danes depicted invading England. Illuminated illustration from the 12th century Miscellany on the Life of St. Edmund (Public Domain)

Sea-faring Danes depicted invading England. Illuminated illustration from the 12th century Miscellany on the Life of St. Edmund (Public Domain)

The intermingling between the Vikings and the Irish is reflected in many of the surnames present in Ireland today: Doyle (son of the dark foreigner), MacAuliffe (son of Olaf), and MacManus (son of Manus), all originate from Viking warriors who married Irish women. Other Norse names found in Ireland include Cotter, Dowdall, Dromgoole, Gould, Harold, Howard, Loughlin, Sweetman and Trant.

Viking Genes in Ireland

It was widely assumed that the genetic contribution of Vikings to the Irish was relatively small, with just a few surviving surnames as their legacy. Supporting this belief was a genetic study conducted in (2006), which showed little remaining signature of the Viking ages in Irish DNA (McEvoy, B., et al., 2006). However, it only examined the paternal line of Irish individuals that carried Norse surnames and used only one percent of available genetic information.

A more rigorous study conducted by the Royal College of Surgeons in Dublin in December, 2017, revealed that the Vikings’ genetic contribution to Irish DNA had been largely underestimated. Their research pieced together a ‘DNA atlas’ using the genetics of 536 Irish men and women. Their results turned up a “surprising level” of Norwegian related ancestry, predominately from counties on the north or western coasts of Norway, where Norse Viking activity originated from.

“The effect of the Norse Vikings on the genetic landscape of Ireland seems to be shared across Ireland, and not limited to regions of Norse settlement, e.g. Limerick, Waterford, Wexford, and Dublin,” the study authors reported in their paper published in the journal Scientific Reports.

Viking longship at Reginald's Tower, Waterford, Ireland. (CC BY-SA 4.0)

Viking longship at Reginald's Tower, Waterford, Ireland. (CC BY-SA 4.0)

Just weeks later, another study concurred that the Vikings made a lasting impression on the DNA map of Ireland. Scientists from Trinity College Dublin (TCD), the Wellcome Trust Sanger Institute at Cambridge, and University College London, mapped genetic similarities and differences between almost 1,000 Irish individuals and more than 6,000 from Britain and mainland Europe. They also found that the Irish have far more Viking ancestry than previously discovered.

“Of all the European populations considered, ancestral influence in Irish genomes was best represented by modern Scandinavians and northern Europeans, with a significant single-date one-source admixture event overlapping the historical period of the Norse-Viking settlements in Ireland,” the study authors wrote in the journal PLOS One.

Unlike the study conducted by the Royal College which found the genetic traces of Vikings spread across the whole of Ireland, the Trinity College study found that the strongest signals were in the south and central Leinster (consistent with the largest recorded Viking settlement in Ireland based in present-day Dublin), followed by Connacht and north Leinster/Ulster. 

“The long and complex history of population dynamics in Ireland has left an indelible mark on the genomes of modern inhabitants of the island” co-author of the study Professor Russell McLaughlin told the MailOnline.

Battle of Clontarf - 23 April 1014 at Clontarf, near Dublin, on the east coast of Ireland. (Public Domain)

Battle of Clontarf - 23 April 1014 at Clontarf, near Dublin, on the east coast of Ireland. (Public Domain)

Ireland Has Not Given Up All its Viking Secrets

Much of Ireland’s Viking history is as murky as the Liffey estuary where a Viking fleet of 60 longships arrived in 837 AD, signalling the beginning of Viking settlements in Ireland. Yet archaeologists and scientists are continuing to clear the muddied waters as new findings come to light that offer a new or deeper understanding of the Viking presence in Ireland.


It was only last month that yet more Viking traces beneath the streets of Dublin emerged. During work at the site of the planned Hodson Bay Dublin Hotel on Dean Street, archaeologists turned up the remains of nine Viking structures, one containing the ‘graffiti’ image of a man riding a horse etched into a slate, leather shoes, a wooden spoon, a wooden bowl, a copper alloy decorated stick pin, worked bone objects, and a rare copper alloy Viking key.

Viking ‘graffiti’ etched on slate of man riding a horse found at Dean Sty, Dublin. Image: Aisling Collins Archaeology Services

Viking ‘graffiti’ etched on slate of man riding a horse found at Dean Sty, Dublin. Image: Aisling Collins Archaeology Services

Professor Clarke suggests the area represents part of a suburban development that existed on the outskirts of the main settlement found at Wood Quay.A map published by the Friends of Medieval Dublin in 1978 contains an orange line indicating a ‘zone of archaeological potential’ and it is here, among other sites across Ireland, that more secrets from the Viking Age are likely to be found.

Together, the archaeological and the genomic research is painting a more complex picture of the Vikings. They were not just warriors, but also farmers, traders, and craftsmen in search of new lands, and they left a permanent mark in Ireland and in the genetic makeup of the Irish people.

Top image: Recreated Viking helmet and weapon (Public Domain); Deriv.

By Joanna Gillan


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Joanna Gillan's picture


Joanna Gillan is a Co-Owner, Editor and Writer of Ancient Origins. 

Joanna completed a Bachelor of Science (Psychology) degree in Australia and published research in the field of Educational Psychology. She has a rich and varied career, ranging from teaching... Read More

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