In the year 1014 AD a battle was fought between the forces of Brian Boru – King of Ireland – and the forces of a Leinster and Viking rebellion. It has become a heroic tale for both sides. As the Annals of Ulster state, “A valorous battle was fought between them, for which no likeness has been found.” This page will discuss the events leading up to Clontarf, the battle itself, and the long-reaching repercussions.

             The Vikings had been raiding in Ireland for Centuries by the time the Battle of Clontarf took place. They conducted extensive raids on the Irish coast in the 8th and 9th Centuries. However, the Vikings eventually began to settle in Ireland (as local populations in Scandinavia grew too large and pushed them out). In 841 the Vikings began establishing winter camps near various rivers in Ireland. One such camp was at Dublin. The Vikings seem to have left Ireland alone for a while, but in 917 they returned and re-established Dublin as a Viking port. They also established other trade towns, such as Wicklow, Arklow, Wexford, Waterford, and Limerick. By the 10th Century many Vikings had intermarried with the native Irish, and many had even converted to Christianity. Until the mid-10th Century the Ui Neill and Eoganachta dynasties had battled for supremacy in Ireland. It was at this time the Dal Cais dynasty from Munster displaced the Eoganachta and took control. Brian Boru was from the Dal Cais dynasty.

             Brian was born in 940 AD and by 976 he had become the King of Munster. In 980 a decisive victory was won for the Irish at the Battle of Tara. Here the king of Meath (Mael Sechnaill II) defeated Olaf Syggtryggsson. This altered the balance of life in Ireland, for now the Norsemen had to pay tribute to the Irish. However, the Vikings still were able to largely control trade, and so were not totally without power. Mael and Brian were two of the greatest powers in Ireland, and in 997 they divided the country between them. Brian had control over Dublin, and Leinster. In 999 Brian and Mael worked together to crush a rebellion led by Sitric Silkenbeard in Leinster. Brian allowed Sitric to return to Dublin as his puppet king. These events were a mere sign of what was to come.

            Family relations also played a role in the making of the Battle of Clontarf. Gormlaith was Sitric’s mother. She had been married three times : to Sitric’s father, to Mael and to Brian. The son of Brian and Gormlaith (Sitric’s half brother) had married into the family of the Viking ruler of Waterford. Brian had also given his daughter to Sitric in marriage. Sitric himself was also the brother-in-law to the king of Norway. This was a complicated family, full of powerful connections. These intermarriages were most likely devised as a way to smooth over feuds. However, this did not stop the battles that were to come. To complicate things further, in 1006 Brian’s son had killed the chieftan of Connaught. This may have made other powerful families uneasy, and perhaps they were even jealous of Brian’s power. For whatever reason, in 1014, the people of Dublin began to make strategic alliances in preparation for a rebellion.

             The Battle of Clontarf took place on Good Friday, April 23, 1014. There are two main texts describing the battle. One was written by Irish authors and titled Cogadh Gaedel re Gallaibh meaning “the war of the Irish with the foreigners.” Another account exists named Brjánssaga – meaning “Brian’s saga” – and is written in Icelandic. Both of these accounts were written about 100 years after the battle, and both contain a fair amount of exaggerations. What seams to have happened is that the men of Leinster organized a rebellion. It seems that Gormlaith may have encouraged Mael to not accept Brian’s rule, and so Mael and Sitric joined forces. After this treachery Brian threw Gormlaith in prison, at which time she somehow contacted the Earl of Orkney for aid. The Isle of Man and the Northern Isles then provided Viking troops for Leinster. Sitric and his men, however did not take part in the battle, but rather watched “from the ramparts” of Dublin. Brian, “aided by the Limerick Vikings” , was victorious and subdued his enemies. However, he was “killed in his tent by fleeing Norsemen.” The Annals of Ulster name his killer as Brotar, “chieftan of the Danish fleet.” The Annals also state that 6,000 men died that day. The author praises Brian, saying that he was the “arch-king of the Gaedhil of Ireland and of the foreigners and Britons, the Augustus of all the North-West of Europe.” The Annals also list other prominent men who died. Brian’s son Murchad, and his son Toirdhelbach both died. Also, Brian’s brothers Donncuan and Cuduiligh were killed, along with many nobles. After the battle, Brian and his son were interred in Armagh. A lengthy ceremony was involved – his body was taken “with relics to Sword-Cholm-Cille and carried thence the body of Brian, King of Ireland, and the body of his son Murchad” and they were “interred … in a new tomb.” This was followed by a 12 night-long wake.

             After Brian’s death his other sons seem to go on to kill their enemies and thus avenge their father’s death. The death of Brian marked a decline in Munster power in Ireland. Eventually Brian’s grandson Turlough would sieze control. It was these later (12th Century ) O’Brien kings who would commission the writing of the Cogadh Gaedhel re Gallaibh. The exaggerations found in this account were meant to cement their authority as high kings. After the battle Sitric is said to have taken a pilgrimage to Rome, and is credited with the establishment of Christ Church Cathedral.

             Both Irish and Icelandic writings about this battle have been viewed as having more literary importance than anything else. It has also been argued that the Battle of Tara was of much more significance in Irish-Viking relations than the Battle of Clontarf was. After Tara, the Vikings were forced to pay tribute to the Irish for the first time in history. Since Vikings fought on both sides at Clontarf, this doesn’t seem to be a fight between two distinct groups, but rather an internal struggle involving all inhabitants of the island. In any case, the story and its characters have proved inspiring for both sides.

William M. Hennesy editor, Annals of Ulster – Vol. 1 (Dublin: Alexander Thom & Co., 1887)

Bernhard Maier, The Celts (University of Notre Dame Press : Notre Dame, Indiana, 2003)

Dáibhí Ó Cróinin, Early Medieval Ireland 400-1200 (Harlow, England: Pearson Education, 1995)

Else Roesdahl, The Vikings (Allen Lane The Penguin Press : London, England, 1987)

Peter Sawyer editor The Oxford Illustrated History of the Vikings (Oxford : Oxford University Press, 1997)

P.H. Sawyer, Kings and Vikings, (London: Methuen & Company Ltd. 1982)
Viking answer lady, (22 May, 2004)

Wikipedia – Brian Boru, (25 January, 2005)

Wikipedia – Battle of Clontarf, (21 November, 2004)