The Battle of Clontarf

Buro and Battle of Clontarf, 1014 Image copyright Ireland Calling

The Battle of Clontarf took place in 1014 and is one of the most significant battles in Irish history.

It is often celebrated as a great Irish victory as the native forces finally saw off a powerful foreign invader – the Vikings.

While the reality is not quite that straight-forward there is no doubt that the Vikings were significantly weakened after losing the battle.

The Battle of Clontarf was fought between the armies of the High King of Ireland Brian Boru and the combined forces of the King of Leinster, Máel Mórda and the King of Dublin, Sitric Silkenbeard, and it was an ill-tempered game of chess that set the wheels in motion.

The Rise of Brian Boru


Brian had become King of the Dál gCais dynasty in AD 976, following the death of his brother. The Dál gCais had risen from being a small kingdom situated near the modern city of Limerick to having the power to control the entire country.

The rise to dominance was started by Brian’s father Cennétig mac Lorcáin and continued by Brian’s brother Mathgamain. It was following his brother’s death that Brian took charge of the Dál gCais and eventually managed to defeat the mighty Uí Néill who ruled the north of the country.

Brian made several enemies on his unprecedented march to power. He was a warlord who ruled by fear. He took hostages to ensure good behaviour from his subjects.

King Máel Seachnaill of the Uí Néill was Brian’s most powerful enemy. The two had fought battles for supremacy for nearly two decades until Máel finally had to submit.

Anger of the King of Leinster

However, it was the King of Leinster Máel Mórda who finally took issue with Brian. Brain had married Mórda’s sister but later cast her aside in favour of another woman. Mórda was waiting for the High King to show a sign of weakness so he could launch an attack.

Mórda had visited Brian to pay homage to him. While Mórda was at the palace in Kincorda he played a game of chess with Brian’s son, Murchad. During the game, Murchad insulted Mórda and the Leinster king stormed away without a word to Brian.

Brian sent a messenger after Mórda in order to bring him back to the palace. However, Mórda was still furious and killed the messenger.

After this incident Brain and Mórda were set for war. Brian couldn’t tolerate the insubordination and Mórda was no longer willing to accept Brian as his king.

The kings recruited their armies

As the two kings recruited allies, cracks started to show in Brian’s power. Mórda was able to outbid him for the support of Sitric Silkenbeard, the Viking King of Dublin.

Silkenbeard was married to Brian’s daughter, but despised the High King and the fact that he had suffered many defeats to him over the years. Mórda offered to restore full power over Dublin to Silkenbeard. Mórda and Silkenbeard then enlisted support from Viking kings from Britain, the Isle of Man, Denmark and Norway.

Brian Boru was able to enlist troops from all over Ireland including Munster, Connacht and the middle of the country.

The forces took their positions

The battle took place on Good Friday, 23 April 1014. It started at sunrise and continued until sunset. The Vikings of the Isle of Man led by Brodir, and of the Orkney Isles, led by Sigurd, were on the front line against Brian’s forces. The Dublin Vikings were next and finally were King Mórda’s forces.

Silkenbeard remained in Dublin with enough men to defend the city.

Buro-and-Battle of Clontarf-1014 Image copyright Ireland Calling

Brian’s Dál gCais forces were on the front line followed by the Munster soldiers, and then came the Connacht forces and the Fergal ua Ruairc, who were Viking allies of Brian.

The Vikings had an advantage that they were wearing chainmail which protected their bodies. The Irish didn’t have such armour but had advantages of their own in that they far outnumbered the Vikings.

Brian was unable to enter the battle field as he was in his 70s. He sent his men north of the river where they burned down the area as far as Howth.

Thousands of casualties

Brian’s son, grandson and brother were on the front line as part of the Dál gCais forces. Murchad, whose disrespectful attitude towards the King of Leinster had set in motion the chain of events that led to the battle, died, as did his 15-year-old son Toirdelbach. Brian’s nephew also lost his life in the battle.

According to the medieval Irish text, Cogad Gáedel re Gallaib (The War of the Irish With the Foreigners), Murchad killed 100 men before he was finally killed.

The Battle was extremely bloody and as the day went on there were thousands of casualties. The forces of the Connacht men came up against those from Dublin. This particular leg of the battle ended with only 100 Connacht soldiers surviving and only 20 Dublin men.

As the day wore on the Leinster and Viking troops eventually buckled, and they were forced back towards the sea. Many retreated to their boats with several more fleeing towards the nearby woods.

However, the tide had come in which meant that they couldn’t reach the woods. The Vikings that were unable to board a ship were ruthlessly killed by Brian’s forces. Many were forced under the water and drowned.

Battle_of_Clontarf Image copyright Ireland Calling

Leaders died in battle

The Death of Brian Boru Image copyright Ireland calling

Brian’s 15-year-old grandson Toirdelbach chased the Viking forces into the sea but was caught by a huge wave and drowned.

Brian’s son Murchad killed Sigurd of the Orkney Vikings but was eventually killed himself. Brodir was leaving the battle field on the shore and went in pursuit of Brian’s tent. When he reached the tent he killed the bodyguard and saw Brian praying. He took the opportunity and killed the old High King by striking him in the head with an axe.

The Munster forces were furious and surrounded Brodir. They closed in on him and cut his stomach open. They then tied the end of his entrails to a tree and made him to circle it until he died.

By the end of the battle it is estimated that between 7,000 and 10,000 men had been killed. King Mórda of Leinster was also a casualty of the battle.

The Vikings power diminished

The Battle of Clontarf is often credited with bringing an end to Viking power over Ireland. It isn’t entirely true. While the Vikings were significantly weakened having been beaten by Irish forces in such a significant battle, in reality their power had been waning for decades.

Nor were the Vikings exactly ‘seen off’. While their power became minimal, many stayed in Ireland and eventually they became totally integrated within Irish culture and society. Silkenbeard remained ruler of Dublin until his death in 1036 and the Vikings controlled the city until at least 1042.

However, they eventually took Christianity as their religion and became ever more integrated with the Irish. Many Irish people or people of Irish descent will have Viking ancestors.

Murphy and Doyle are two famous Irish names that came from the Vikings. The Viking towns continued to grow and to this day remain the major cities in Ireland.

Boru's dynasty comes to an end Image copyright Ireland Calling

The Battle brought an end to the rule of Brian Boru. With his son and grandson also dying in battle, the dynasty lost its grip over Ireland and the country went back to being a collection of small kingdoms, all constantly at war with another.

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