The Battle of Clontarf took place on April 23, 1014, near Dublin, Ireland. It was a significant conflict between the forces of the Irish king Brian Boru and a coalition of Viking invaders and their Irish allies. The battle was fought to end Viking influence in Ireland and to assert Irish sovereignty. Despite being outnumbered, Brian Boru's forces achieved a decisive victory. However, the battle resulted in heavy casualties on both sides, including the death of Brian Boru himself. The battle marked a turning point in Irish history, leading to the decline of Viking power in Ireland.