Analysis: what we've learned about our ancestors from analysing DNA found in four of Ireland's Viking burials

Nature recently published a major new study declaring that the Vikings were not blonde-haired but, in fact, probably had black hair. Casting directors across the world must have held their breath in shock at the thoughts of re-casting all their TV Vikings with black hair. This insight comes from analysing the DNA contained in tiny fragments of bone and teeth from 442 Viking burials across Europe, including four of Ireland’s Viking burials.

These Viking graves are easy to identify as Christians usually buried their dead in simple graves without gravegoods looking east in graveyards. Against this orderly backdrop, Viking burials stand out as unusual, foreign and deviant from the norm.

A typical Viking warrior in Ireland was buried with a sword (imported from Scandinavia), a spear and shield (both showing local manufacture). Axes are rare in our graves. Viking women were buried with pairs of oval brooches and beaded necklaces, again imported from Scandinavia. The high quality of goods indicate that these were special burials. The swords in particular stand out: the expertise of the swordsmith and the quality of steel mean that a Viking sword is equivalent to a Ferrari. Burying that Ferrari in the grave is a real statement of wealth, excess and importance.

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From RTÉ Radio 1's Drivetime, Dr Lara Cassidy and Maeve Sikora on what we've learned about Vikings from new DNA findings

The first burial was found on St. Patrick's Day 1947 in a Galway sand-dune. It was that of an unusually tall man - at 1.75m tall, he literally stood out in Connemara - and skeletal analysis indicate that he limped and did a lot of heavy lifting as an adolescent. This was a man in his early twenties buried with a full set of Viking weapons - sword, spear and shield. There are no radiocarbon dates, but our best estimate is that this warrior was carefully buried less than 50 metres away from the Atlantic Ocean sometime between 850 and 925AD.

The Nature study analysed the ancestry components of the burials, noting that this male had a mixed British/North Atlantic /Norwegian ancestry. Galway is not thought to be a traditional Viking stronghold, but it was the site of many raids. Perhaps this man was a casualty of a raid gone wrong, buried like a true Viking on foreign soil, or perhaps he was the first of many Scandinavians attracted to life on the Wild Atlantic Way.

The three Dublin burials come from Finglas (well-trodden Viking territory, even the name 'Fine Gall’ means foreigners), the War Memorial Park in Islandbridge (close to the biggest Viking burial place in Ireland), and Ship Street Great in the heart of Dublin. In 2002, archaeologists at Ship Street Great uncovered the skull and torso of a man in his late twenties. This man was buried with a sword and wore a leather/fibre necklace carrying silver rings and a bead. This burial’s ancestry signal is over 80% British/North Atlantic, indicating that he came from the Viking colonies in northern Scotland rather than Norway.

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From RTÉ Six One News, skeleton of Viking child found during Dublin excavation

This ties in with oxygen isotope analysis which shows that two more Viking burials from nearby South Great Georges Street also came from northern Scotland. The Ship Street burial was later linked to two more Viking burials excavated in the graveyard of St. Michael le Pole. All three of these burials were oriented east-west and placed with their gravegoods on the edges of the graveyard. This shows that the incoming Vikings and the local Christians interacted peacefully enough to come to an agreement about mixing Viking and Christian burial rites.

A Viking woman was buried in Finglas sometime in the late 9th century. Rather than weapons, her gravegoods included a pair of Viking oval brooches, a wooden casket and a bone haircomb. These brooches date to the middle of the 9th century which allows a couple of decades for the brooches to make their way from Scandinavia to Ireland. 

The woman was aged 25 to 35 years old when she died, and her ancestry signal indicates an 80% Norwegian signature. There are two possibilities here: one is that this woman came from Scandinavia as a grown woman, perhaps a Viking bride for an Irish ally. Alternatively, she came as a child with her family, some of the first Norwegian Vikings to relocate to Ireland in the 9th century. When she passed away, her family honoured her Scandinavian origins by providing her with a Viking- burial including her treasured oval brooches.

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From RTÉ Six One News, how an archaeological dig has changed the picture of Dublin's earliest Viking settlement

The last burial from Islandbridge contained a Viking sword, an Irish spearhead, a simple ringed pin, and parts of two weighing scales (the Vikings operated by barter when it came to buying, selling and redistributing their raiding booty). These artefacts all indicate a date in the first half of the 9th century. The osteoarchaeologist identified the heavily disturbed skeletal remains as those of a young man, aged around 18-20. Oxygen isotope analyses indicate that this teenager grew up in Scandinavia and must have been a relatively recent arrival to Dublin. Unfortunately, the scientists were unable to include this sample in the ancestry analysis so we cannot confirm these suggestions. 

It is impossible to identify the cause of death of these people, but every one of these burials was marked out by their adherence to Viking traditions. The Finglas and Ship Street burials indicate close contact between Dublin’s Viking and Irish populations, while the Eyrephort and Islandbridge burials display stronger Viking tendencies (perhaps supported by the inclusion of multiple weapons). These burials all came from the same genetic Norwegian/North Atlantic ancestry. This indicates a relatively closed circle of Norwegian/North Atlantic Vikings immigrating to 9th century Dublin. This was not a diverse population and will prompt new questions about just who founded Dublin, our first town.

And did these Vikings have black or blond hair? Well, the comparison population used in the Nature study was Danish, not Norwegian. As our Vikings seem to be Norwegian, we are still free to fill our TV screens with blond-haired and blue-eyed Norwegian Vikings, which should provide some relief to casting directors.


The views expressed here are those of the author and do not represent or reflect the views of RTÉ