Which Irish high king was killed at the Battle of Clontarf in 1014?

The Irish high king killed at the Battle of Clontarf in 1014 was Brian Boru.

Brian Boru, also known as Brian Bóruma, became the dominant ruler in Ireland after defeating rival kings and building a powerful political coalition. His forces met an army associated with the Dublin Norse and their allies at Clontarf, near Dublin, on 23 April 1014.

The battle ended the immediate challenge to Brian’s authority, but it was not simply an Irish-versus-Viking conflict. Irish kings and Norse-Gaelic forces fought on both sides, and the Norse ruler of Dublin, Sitric Silkbeard, was connected to the opposing coalition. Brian was killed after the fighting, reportedly by the Norse warrior Bróðir.

Later tradition often presents Clontarf as the moment that expelled the Vikings from Ireland. In reality, Norse communities, trade and political influence continued in Ireland for centuries afterward.