The Battle of Clontarf takes place on Good Friday, April 23, 1014, at Clontarf, near Dublin, on the east coast of Ireland. The battle is the culmination of two centuries of strife, treachery, failed alliances and treaties that pits the forces of Brian Boru, high king of Ireland, against a Norse-Irish alliance comprised of the forces of Sigtrygg Silkbeard, king of Dublin, Máel Mórda mac Murchada, king of Leinster, and a Viking contingent led by Sigurd of Orkney and Brodir of Mann.

The first Norsemen, also known as Vikings, arrive in Ireland some two centuries earlier, initially plundering the gold, chalices, crosses, and manuscripts of the monasteries and the corn harvests of the settled communities. Gradually they establish Viking settlements around Ireland and engage in trade and commerce.

There is, however, significant opposition to their presence in Ireland, not least in Munster where King Brian Boru has defeated their armies on several occasions. Brian’s aim is to unite all the warring Celtic kingdoms under one rule and one High King.

In 1013, Máel Mórda, the king of Leinster goes into revolt after inter-marriage alliances with Brian have broken down and joins forces with the Vikings. Together, they initially attack the kingdom of Mael Sechlainn of Meath who summons the help of King Brian. Brian sets off toward Dublin with 4,900 troops. Opposing them are Máel Mórda’s army of 4,000 Leinster men allied to 3,000 Viking warriors.

Although but a small segment of the battle is fought close to the seafront at Clontarf, the historic encounter of Good Friday 1014 enters the annals as the Battle of Clontarf. This is largely because some 2,000 Vikings had landed in longboats at Clontarf by sunrise on the morning of April 23.

As the two opposing armies face one another, the Vikings and the Leinster men are lined across the sloping plains bounded by the sea and the River Tolka, while King Brian’s army occupies the rising ground near Tomar’s Wood in Phibsborough.

The most ferocious part of the battle is fought at the “Battle of the Fishing Weir,” which approximates to the site of the former D.W.D. Whiskey Distillery on Richmond Road. Historic accounts of the battle also refer to the “savage encounters” fought on the “Bloody Fields of Marino” and what is today Phibsboro and Cross Guns.

The result of the bloodiest day in ancient Ireland is a rout for King Brian, although some 4,000 of his troops are killed on the battlefield. In contrast some 6,000 Leinster men and Vikings are slaughtered including every single Viking leader. King Brian’s army drives the fleeing Vikings back towards the sea at Clontarf.

Although Brian has won the greatest victory of his long career, he does not live long to enjoy it. As he kneels praying in his tent near Cross Guns, the Isle of Man Viking Leader, Brodir, who is hiding in the adjacent woods, runs into his tent and kills the 84-year-old Brian with his axe. Brodir is later captured and slaughtered by Ulf the Quarrelsome, the younger brother of King Brian.

The Battle of Clontarf is the watershed of all the hatred, division, and rivalries that have consumed Ireland for centuries. A period of relative peace follows where the Celtic chieftains and the Vikings live together in a spirit of harmony with the emphasis on greater integration, cooperation, and commerce.