Brian Bóruma mac Cennétig (926 or 9411 – 23 April 1014) (known as Brian Boru in English) was High King of Ireland from 1002 to 1014.
Brian Boru was a Christian, he had battled the ancestor's of the O'Neill's for many years and was the rebuilder of Viking-ravaged monastaries and churches, Boru also built forts, and at the age of 74 he commanded an army of thousands, he battled royally against the Viking soldiers, his army slaying some 7000 Vikings.
In 1005 AD Boru reached Armagh, leading several armies from, Munster, Leinster, Meath, Connacht and Norse Dublin. He had come to the North two times previously, only to be repelled by the Ulster kings. The Church had recognized Boru's claim to supremacy after he paid 20 ounces of gold to have the Church inscribe his name in the Book of Armagh as the "Emperor of the Irish". A year later he established his claim with a circuit around Ulster. But Brian had difficulties, the Leinster and Dublin armies called in allies from the Viking world, creating the scenerio for the battle that lead to Brian's death.
It was Good Friday in the year 1014, and the battle lasted from sunrise to sunset. The battle was called the "Battle of Clontarf" and was also known as the Battle of Brian, and it ended the domination of the Ui Neill, the ancestors of the O'Neill's of Tyrone and Clandeboye.
Brian Boru was killed in his tent, by King Brodar of Man, following Clontarf and 4000 other Irishmen also died that day, still King Brian was considered triumphant. He was killed along with Sigurd, who was Earl of the Orkneys, the King of Leinster, also two Connacht kings were slain, and Brian Boru's son, Murchadh were all killed along with many others of noble blood.
Brian Boru is remembered as one of the greatest hereos of all Ireland because he ended any hope of the Viking's ever capturing Ireland. Brian Boru reportedly had 4 wives and 30 concubines and many, many Irish families trace their ancestral heritage to Brian Boru.