The Vikings

The Vikings would be one of the most powerful influences on Irish life for the bones of 400 years. They first show up in the late 8th century and there were still Viking kings in Ireland when the Normans arrived almost four centuries later.

Last updated: 12 Feb 2024

​In the medieval period, rivers and lakes were the principal highways that people used to get around. i The rivers of Ireland – and, in fact, most rivers in Europe - were considerably swampier, broader and a lot less navigable then than they are now. It required humans to beat them into shape with navvies and dredgers and so on.

As these rivers were the main transport network, many people within Ireland opted to build their communities, homes and villages along or close to the waterways. Monastic schools and hermitages sprang up along many rivers and lakes. There were twelve island monasteries on Lough Erne and plenty of other on Lough Ree and Lough Derg. Such locations might seem remote today but, a thousand years ago, an island monastery was like a ringside seat on the great watery highway. A direct link to the island’s main transport system. That works very well if you’re trying to shift things around, whether it be passengers, or monastic students, or animals, or food supplies for the coming winter.

However, what happens when a darker force gains access to those same waterways? A force like the Vikings, whose sole game-plan seems to be to raid and plunder and generally go on the rampage? The Vikings would be one of the most powerful influences on Irish life for the bones of 400 years. They first show up in the late 8th century and there were still Viking kings in Ireland when the Normans arrived almost four centuries later. 400 years is a long time, equivalent to us going back to the 1620s … and look at how much has happened since the 1620s!

There’s a decent chance that you have some Viking DNA circulating in your bloodstream. We are surrounded by Viking names, not least because there was a lot of intermarriage over those 400 odd years, while many of the indigenous Irish took up the Viking way of life. Reynolds, Higgins, O’Loughlin, McAuliff, Rourke and Dowdall are all generally said to have been of Viking origin. Doyle might be another. Most of the Vikings who came to Ireland were from the north and west coasts of Norway, while others hailed from Denmark or Sweden. Norse warriors seem to have had brown hair, rather than the blonde hair we generally associate with Vikings. In fact, they didn’t call themselves Vikings and nor did they wear horny hats but let’s not spoil the story too much. Besides, Vikings is a term we can all relate to. That’s why the hit TV series was simply called ‘Vikings’. Most of it was filmed in County Wicklow, which means ‘meadow of the Vikings’ in Viking lingo, and the fact they managed to squeeze 89 episodes out of the show - six seasons all told – indicates an immense demand for Vikings on-screen. Indeed, they also managed to generate three seasons for its sequel ‘Vikings: Valhalla’, not to mention 46 episodes, spread over five seasons, of the semi-Viking Netflix mini-series ‘The Last Kingdom.’

Whether the Vikings were driven by volcanic climate change, or their thirst for adventure, or the need to acquire land in other places, or whatever it was, these fearless warriors would control, or certainly be a major player on the Irish seas through most of the 9th, 10th and 11th centuries. They dominated all the seas around Ireland and Britain, or much of it. They were also the foremost powerhouse on the Isle of Man, along the north-west coast of Scotland and north to the Orkneys and the Shetlands right up to Iceland. In due course, the Vikings would make an impression in places as far away as Morocco, Istanbul, Russia, Ukraine and North America. They seem to have viewed the world as a very big watery highway!

So now let us, like them, home in on Ireland, a land celebrated for its Christianity replete with monastic schools where European aristocrats sent their children to be educated. They are sanctuaries of peace and contemplation but word is out that they are also sanctuaries of wealth. Some of it is agricultural wealth, the fruits of its well-run farms, but there is also plenty of religious bling - chalices, bejewelled crosses, processional crosses, tapestries and so on.

One might think such wealth would invite the local clans to attack, and sometimes they did, but mostly they did not because the Irish were now, by and large, a Christian people. A few centuries earlier, they were more like the Vikings and believed in a whole pantheon of different gods. But now, being Christian, they were scared that their souls might burn in purgatory for ever more if, say, they broke into an abbey and robbed a golden chalice. 

Such qualms were irrelevant to those who did not believe in purgatory, or Christian gods, like, say, a Viking warrior with a boat and a compass who learns about these sprawling, undefended communities stuffed with golden chalices and barns full of food.

The Viking raids kicked off in the 790s. There may have been earlier ones, but the big date given is 793 when they attacked the island monastery of Lindisfarne off the coast of England. They killed nearly everyone there and took the survivors off as slaves. When you read the reaction to Lindisfarne, it’s like the White Walkers have arrived if you know your ‘Game of Thrones’, or the Fungus Zombies from ‘The Last of Us’. As one Anglo-Saxon scholar wrote: ‘Never before has such terror appeared … as we have now suffered’.

Soon enough, these terror-inducing pirates were heading for Ireland. They started with the outlying islands – Rathlin, Lambay, Inishmurray, Inishboffin and right down the west coast to the Skelligs and Valentia off the kingdom of Kerry. These attacks were generally straight-up hit and run affairs where they would kill the monks, steal the goods, and skedaddle.

The same thing happens along the coast of Scotland. Iona, the monastic retreat founded by St Columba long centuries earlier, is hit again and again until 806 when 68 members of its community were killed. Iona is where they created the magnificent Book of Kells. Part of the miracle of that book is that it has led such an epic life. It is the story of the book as much as the book itself. For instance, the monks got it out of Iona in the nick of time before that final deadly Viking attack. They somehow sailed the book across the sea to Ireland and got it to Kells Abbey on the Blackwater, a tributary of the River Boyne, in County Meath. The monks presumably hid the book in Kells because they figured the Vikings would never dare come up the river. Or would they? Well, yes, they would.

By the year 840, there was a change in strategy by the Vikings. Prior to 1840, they are all about the annual hit and run attacks after which they beat it back to the fjords of Norway or Denmark or wherever they came from. Starting in about 840, they change tack. They decide to stay around, to spend the winter in Ireland where they can plan a new spring campaign. Why waste time paddling back to the fjords when one could build a village of wattle cottages and make a base in Ireland?

Thus they start building longphorts - defended, sheltered harbours, or ship-camps – which would gradually spring up at the mouths of every significant river in Ireland. In time, these Viking winter-camps would evolve into Ireland’s biggest cities - Dublin, Cork, Waterford, Limerick, Drogheda, Wexford and such like.

At the peak of their power, the Vikings had a veritable chain of camps controlling the entrance to all of those rivers, and blocking the exit too. They also began to head up those rivers for a little plunder when the fancy took them. The Shannon, the Erne, the Barrow, the Bann and the Boyne would become their new playgrounds.

One of the principal Viking figures was called Turgesius. I’ve opted to pronounced his name Thorgesius because there’s a nice touch of Thor there, but his name is written in a bunch of different ways such as Tuirgeis, Turges, Thorgest and Thorgil. Turgesius was a Viking warlord, probably Norse, but we are kind of on the cusp of mythology and fact here. What we know, or think we know, is that Turgesius first appeared on the Irish waters in about 820. He may have been with the Vikings who appeared in Belfast Lough in 823 and killed the Bishop of Bangor. Perhaps he was also with the Vikings who made their way up the River Erne in 822 and burned the monastery on Devenish Island.

Maybe he went away for a while, maybe he stayed around. Who knows!? I feel that he’s the sort of guy who would have orchestrated the attacks in the big bad year of 836 AD when, as the Annals of Ulster record, “all the churches of Loch Erne, together with Cluain Eois [Clones] and Daimhinis [Devenish Island] were destroyed by the gentiles.”

Clones! Now Vikings are sea pirates but Clones is a long way from the sea. These same warriors probably ventured into the Lough Head, near Lisnaskea, on Lough Erne. They also appear to have been on the Colebrooke River, which connects Lough Head to the Erne. The fact that ‘all the churches of Loch Erne … were destroyed!’ is no surprise although some say the Viking reputation for total destruction was exaggerated. The argument runs that a wise Viking leader would have seen a monastery as a golden goose that kept on laying so raid them, yes, but then let them flourish anew, and then attack again.

                                                            Clones Round Tower, Courtesy Monaghan Tourism

They assuredly wanted plunder. Books, not so much. But precious stones and metalwork and gold, yes. And food, yes. Bear in mind there would have been substantial stores of provisions in monastic communities, which is just what you need if you’ve got a few thousand warriors looking for some food for the long winter.

The Vikings also liked people. As in, they liked to enslave people and sell them on. On the Vikings watch, Dublin would become one of the great slave centres of Western Europe. And who started that? Well, we’re back to our friend Turgesius. He is credited with founding the city of Dublin in 841 when he apparently built a fort on a hill right where Dublin Castle is today. It had a harbour beside it where they could fit 200 ships, which became a trading centre for the Gall-Gaildal (ie: a sort of Norse-Irish mixed community). The monks called it Dubh Linn, the black pool, and the Vikings ran with the name. Dublin it is.

Now, I don’t know if Turgesius was really the guy who started Dublin but he was certainly knocking around at this time. The annals say he had a fleet of 120 ships by 837. That’s a massive fleet. It’s not clear whether these were longships, but an average longship could carry between 25 and 60 people so 200 vessels might translate into several thousand Vikings. Or maybe there was more, feasibly a lot more. Either way, that’s a whole lot of Viking.

Turgesius split his fleet in two, sending half up the River Boyne – so good luck to the monks trying to hide the Book of Kells – and the other half, the other sixty ships, up the Liffey. However, given that he now has potentially several thousand warriors beating their chests looking for plunder, he needs to spread his wings. He could go east and harass the coast of Wales or the Isle of Man, but instead he opts to push further into the Irish interior.

By 839, the Vikings have sailed up the Bann into Lough Neagh, where they wintered in 839, 840 and 841. Come each spring, they would set out and plunder the churches of Ulster. Turgesius himself went south to Lough Derg and the Shannon where they burned Inis Caltra monastery to the ground in 836. (The Vikings would destroy it again nine decades later). Vikings had been on the Shannon since at least 815 when they raided the monastery on Scattery Island, killing any monks they found. They would return to Scattery for repeat attacks again and again until they settled on the island in the 10th century.

The Vikings levied heavy tributes on the native Irish who survived their quest for blood. Some claim the term “nose-money” or “nosegelt” derived from these tributes because the standard punishment for those who failed to pay was the removal of one’s nose. 

Imagine how terrifying it would have been if you were a monk or a nun or a farm-boy living on the edge of the Shannon when word reaches you that Turgesius’s fleet was on the way, destroying – it is said – all that is in his path.

Turgesius took a shine to Lough Ree, where he is said to have established a base on the Rindoon peninsula. Hare Island at the bottom of Lough Ree was also the site of a reputed another Viking encampment, while there were others on Lough Lene in County Westmeath where one island fort still bears his name.

From Lough Ree, the Vikings attacked all the places within range such as the monastic schools at Clonfert and Clonmacnoise and the monasteries of Lorrha and Terryglass, and everything in between. As one contemporary chronicler lamented: “Increasingly from hundreds of monasteries rose to Heaven the mournful litany- A furore Northmanorum libera nos Domini’- ‘From the fury of the Northmen save us O Lord’.

Turgesius was an especially familiar face at Clonmacnoise where some say he had a fortress of some form there. Legends claim that he declared himself Abbot of Armagh and made it a base for himself and his wife, Ota, who is described as a völva, which is like a seeress or a sorceress. It rather depends on who you read but some say they went into the church at Clonmacnoise and recited pagan chants from the ruined high altar, while others say they danced naked and engaged in other lewd acts. I can’t tell you what the truth is because, luckily, I wasn’t there.

Turgesius was finally slain in 843 or 844. His killer is said to have been Máel Sechnaill I (or Malachy), King of Meath. The story is that Malachy sent the Viking warlord a gift of his own beautiful daughter, accompanied by fourteen comely maidens. So smitten was Turgesius that he failed to realise the fourteen comely maidens were assassins in disguise. The assassins tied him up in chains, placed him in a barrel and rolled him into Lough Owel near Mullingar, where the tyrant drowned. He lives on in a sculpture in Mullingar Town Park entitled 'The Norse and The Gael’, carved from a condemned ash tree with a chainsaw by wood carver Richie Clarke. In the work he depicts Malachy, with an Irish Wolfhound above him, to represent the Irish, while Turgesius is accompanied by a Norse dragon. The bough coming out has an image of the Celtic war goddess, The Morrígan.

The death of Turgesius must have been very welcome on the Shannon and there was definitely an easing of Viking activity in the region for a long time afterwards. Or perhaps the Vikings had other fish to fry. In 845, the year Turgesius dies, the Vikings launched their first attack on Paris.

That era of attacks had been a dark one for the monasteries and a huge challenge to the church’s education system and culture. More’s the pity because there was actually quite a promising sense of humour in the writing and poetry coming out of some of those monasteries in the period just before the Vikings. Afterwards, much of their writings were coated in feelings of grief and fear and darkness.

Looking for positives, the Vikings may have been responsible for the introduction of saunas to Ireland. It is said that Danes raiding up the Shannon introduced the custom. Saunas, or sweathouses, were known in Finland at this time - if anyone knows more of Shannon-side saunas, I’m all ears. Sticking with Finland, it seems the moiled cows they have in Finland today are descended from moiled cows that were nabbed by Finnish Vikings back in the day.

The Vikings were evidently zooming in on every river in Ireland by the 9th century. In 824, a fleet of Vikings sailed up the Barrow from Waterford to St Mullins where they may have established a settlement. The Vikings seemingly lost a big battle at St Mullins in 888, after which 200 heads were left behind. On the same river, they had a longphort, an oval fort, at Dunrally, near Vicarstown, Co. Laois. Enclosed by the Barrow and a tributary called the Glasna River, this provided safe anchorage for Viking ships. It is possible that this was the longphort referred to in the annals as being built by a Viking called Rodolf and destroyed in 862. By extension, Rodolf might be the same Rodolf who showed up on the river Rhine with a fleet of Viking ships that same year. With so much interconnection in this Viking world, that cannot be ruled out.

    St. Mullins, Co. Carlow. Courtesy Luke Myers  

Things went downhill for the Vikings in 902 when they were kicked out of Dublin with such force that they moved to northern Britain and the Isle of Man. The warriors wandered for a while and then regrouped before directing their ships to the coast of Munster. In 914, a mighty Scandinavian fleet arrived from northern France into Waterford. Their arrival was described in a contemporary manuscript called Cogad Gáedel re Gallaib ("The War of the Irish with the Foreigners"), composed sometime between 1103 and 1111 for the O’Briens.

‘The Earl Oiter Dubh [the Black Otter] came with a hundred ships to Port Lairge [Waterford] and the east of Mumhain [Munster] was plundered by him, and its south, and he put all under tribute and service to the foreigners; and he levied his royal rent upon them. The whole of Mumhain became filled with immense floods and countless sea vomitings of ships and boats and fleets so that there was not a harbour, nor a landing port, nor a Dún nor a fortress nor a fastness in all Mumhain without fleets of Danes and pirates …’

‘There came there also the fleet of Oiberd and the fleet of Oduinn and the fleet of Griffin and the fleet of Snuatgar and the fleet of Lagmann and the fleet of Erolf and the fleet of Sitriuc …’

The author goes on to name nine more fleets, 16 in total, that arrived into Ireland at this time, and concludes ‘And assuredly the evil which Erinn [Ireland] had hitherto suffered was as nothing compared to the evil inflicted by these parties.’

The last of those sixteen fleets was commanded by the Inghen Ruaidh, known as the “Red Girl”, so a red-haired shield maiden was leading her fleet of longships onto Irish shores.

These guys were not here to go trout fishing. Munster was devastated in 915. Two years later, the Norse won a major battle at Confey, annihilating the Irish and leaving 600 dead, including the king of Leinster. The battle is said to have been fought just outside St Mullin's in the valley of Glynn, on a small tributary of the Barrow. From here, the Vikings then rolled on up through Kildare, attacking Castledermot, and founded Leixlip in north Kildare as the most westerly outpost of the Viking Kingdom of Dublin. Its name is of Scandinavian origin and derives from the old Norse for ‘Salmon Leap’ – ‘Lax-hlaup.’

In the wake of the battle, they also retook Dublin and then consolidated their position in 919 by defeating the Irish in battle at Islandbridge and killing Niall Glúndub, the High King. Over the next decade, the Vikings founded numerous harbours and ports along Ireland’s south coast. The earliest archaeological evidence of a Viking settlement in Waterford has been carbon dated to between 898 and 920, which correlates to this wave of Vikings. They also took over Cork and actually developed quite a nice wine trade with France at this time. In the 920s and 930s, a Limerick-based warlord called Olaf had a pretty powerful fleet on Lough Ree with which he actually defeated an army of Dublin Vikings along the way.

The fact that the Vikings were on the rise again across Ireland was reflected in the Annals for 923 which noted “a fleet of foreigners on Loch Erne and they plundered the islands of the lake and the territories round it to and fro.”

From this point until the arrival of the Normans, there is another shift in Vikings strategy as they exchanged the life of a plunderers for that of a settler. They became farmers and traders, established colonies and towns, gave up on their old gods and converted to Christianity. Meanwhile, they were also sucked into the never-ending game of thrones in pre-Norman Ireland with incessant wars between the kings and mini-kings.

The biggest king of all was the top-ranking Viking basher, Brian Boru, or Brian Bórama, of the Dál Cais dynasty. His hometown of Killaloe in County Clare lies on the River Shannon on the western bank of Lough Derg. Brian’s brother Marcán was abbot of Inis Caltra, Holy Island, in Lough Derg and Brian is said to have built one of the churches on the island. Killaloe was also full of churches: St Flannan's Cathedral has just celebrated its 800th anniversary.

Holy Island, Lough Derg. Courtesy Gaelforce Great Lake Swim

King Ivar of the short-lived Norse kingdom of Limerick made the mistake of burning some of Brian Bórama’s churches. Brian took exception to this and so King Ivar of the short-lived Norse kingdom of Limerick was driven out of his base at King’s Island on the Shannon in central Limerick, where St John’s Castle is now. He took refuge on other islands in the Shannon before creating a new Viking stronghold in Inis Cathaigh, now Scattery Island. Located at the mouth of the Shannon, the island gave him kind controlled of all maritime traffic up the Shannon. (I believe Bunratty Castle stands on the site of a Viking camp from this time also.)

King Ivar had two sons, whose names translate as Wild Dog and Dark Head; they wouldn’t sound out of place in an Electric Picnic line up. The trio were ambushed and killed by Brian Boru in 977, after which Brian trounced the Vikings at the battle of Clontarf only it’s a whole lot more complicated than that because the Vikings were kind of Irish and the Irish were kind of Viking and nobody’s quite sure what really happened anyway.

There was also a major showdown on Lough Ree in 997 between Brian Boru and the High King, Máel Sechnaill. Brian Boru apparently fielded 300 ships, which is quite some force, but for once diplomacy prevailed and nobody got hurt.

In 997 Brian Boru, now King of Munster, apparently assembled a great fleet, or cabhlach mór, of 300 ships into Lough Ree to take on the High King, Máel Sechnaill. The ships were not all his; many belonged to his Vikings, or Hiberno-Norse, allies. For once diplomacy prevailed when Brian and Maelshechlainn decided to talk it out at either Clonfert or Inny Bay, at the mouth of the River Inny. They decided to split their claims to the country, so Brian got the southern half, Máel Sechnaill got the north, and everyone lived happily ever after … for a while.

Some Vikings became restless in Ireland where they were constantly being beaten in battle and losing their cities. The Irish had the upper hand, and it was becoming too much effort to stay. Throw in a huge blast of radiation from the Sun that hit Earth in 992AD and you start to see the Vikings head further afield. Some would head north-west to places as far away as Iceland, Greenland and even Newfoundland. They were accompanied by their Irish wives, daughters, concubines, foster children and the enslaved, which helps explain why there is so much Irish DNA in Iceland today.

However, many more Vikings opted to stay in Ireland and their legacy is all around us. That’s why we celebrate the gods Odin, Thor and Frija every Wednesday, Thursday and Friday. Believe you me, there’s still plenty of Vikings in your parish.

Meanwhile, a new group of Vikings or Northmen, were sharpening their swords and preparing to head to Ireland. These were the Northmen who had conquered England in a single battle in 1066, the battle of Hastings. We know them as the Normans.



i I like how the historian Dan Carlin put it – the rivers are like a giant subway system.

Further Reading

  • Bunbury, Turtle,'Ireland's ‘Ireland’s Forgotten Past’ (Thames & Hudson, 2020)

  • Clark, Michael, The Sailing History of Lough Erne, Clogher Record, Vol. 18, No. 3 (2005), pp. 501-540

  • Livingstone, Father Peadar, ‘A Fermanagh Story’ (Cumann Seanchais Chlochair, 1969)

  • Martyn, Adrian (2016). ‘The Tribes of Galway, 1124-1642’

  • Simms, Katharine. “The Medieval Kingdom of Lough Erne.” Clogher Record, vol. 9, no. 2, 1977, pp. 126-141.


Researched and written by Irish historian Turtle Bunbury, the history of Irish Waterways and their environs is the result of extensive original scholarship through the National Archives and contemporary newspapers, as well as the expertise of local historians and academic historians.


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