The Battle of Clontarf took place outside the city of Dublin on Good Friday in 1014. On the one hand, Brian Boru led the Irish in resistance against the Dublin Vikings, who were supported by Vikings from England, Scotland, the Isle of Man, France and Orkney Islands.

Born around 940, Brian Boru was an inhabitant of Co Clare and belonged to the royal house of Thomond. At this point in Irish history, Viking raiders had taken over the island. From an early age, Brian led his followers against the Vikings, who at the time ruled large coastal areas around Ireland. He defeated them in several battles and finally managed to drive the Vikings out of Munster. After his older brother Mahon was assassinated in 976, Brian Boru became King of Munster. In 1002 he became king of Ireland and his main objective thereafter was to eliminate the Vikings from the whole country.

Finally at the Battle of Clontarf the Vikings of Ireland were defeated. Irish losses were estimated at 4,000, including their king and most of his sons, however, of the 7,000 to 8,000 Viking and allied forces, an estimated 6,000, including almost all the leaders, were killed.

At the end of the battle, the Viking forces close in on their ships. During this retreat, the Irish fighters were negligent in leaving Brian’s tent unprotected and a group of fleeing Danes and their leader Brodir killed him with an ax while he was kneeling in prayer.