Brian Bórúma mac Cennetig, known popularly as Brian Bórú, is undoubtedly the most well known ard-rí (ARD-ree) or High King of Ireland of Ireland and arguably the only ard-rí who, like Ælfred the Great of England, actually controlled the entire country.
     Brian Bórú was born circa 941 at Béal Bórú (from which he received his name), near Killaloe, County Clare, at a time when the Norse had secured many seaports and frequently plundered and harried the neighbouring countryside. In 976 he succeeded his brother Mathúin as king of Dál gCais and claimant to the kingship of Munster. By 999, after a series of wars, he was acknowledged as High King of Ireland.
 

The Battle of Clontarf

    Brian Boru's reign was marked by continuous opposition. This came to a head in the early eleventh century. Máel Mórda, the king of Leinster, made an alliance with the Dublin Norse under Sigurd, Earl of Orkney and their overseas allies. Brian's forces defeated this union at Clontarf, about four miles north of modern Dublin, on Good Friday, April 23, 1014.  Brian, too aged to fight, was awaiting news of the battle when he was slain in his tent by a Viking intruder. The battle of Clontarf marked the end of any major Viking involvement in Irish wars.
    From this point on, the role of the Norsemen in Ireland was largely peaceful, and they intermarried with the Irish and concentrated on developing trade.  However, with the death of Brian Bórú in 1014, Ireland once again became an island of conflicting dynasties, with the High King unable to enforce acceptance by all the provinces.

A youngster attempted to defend the ageing Brian Bórú, High King of Ireland, from attack by a fleeing Viking warrior. Good Friday, April 23, 1014.

    While Brian Bórú's ancestry depends solely on tradition and is not accepted as proven, we have two definite links with regard to his descendants.