Toirdelbach Ua Briain - Background

Background

Brian Bóruma was the first man in many centuries to establish himself as High King of Ireland almost purely by force of arms. Previous men reckoned High King had belonged to the great Uí Néill kindred, the large group of families who claimed to descend from Niall of the Nine Hostages, which dominated much of central and northern Ireland from the 7th century onwards. No king from the south, where Brian's kindred, the hitherto rather obscure Dál gCais of the region of Tuadmumu (north Munster), had come close to dominating Ireland since the time of Feidlimid mac Crimthainn in the early 9th century, and none had been included in the more widely accepted lists of high kings in historic times. The last effective high king of Ireland from Munster was Cathal mac Finguine (d. 742), and likely before him the prehistoric Crimthann mac Fidaig.

Brian, building on his own resources and those of the Viking towns of the south such as Limerick and Cork, first took control of Munster, overthrowing the domination of the Eóganachta, a kindred which had dominated the kingship of Munster as effectively as the Uí Néill had dominated the High Kingship, and for just as long. With the Uí Néill disunited and the resources of Munster at his command, Brian first brought the Uí Néill High King Máel Sechnaill mac Domnaill to recognise him as an equal, and then to acknowledge him as the master of Ireland. Brian met his death at the Battle of Clontarf on 23 April 1014—Good Friday—fighting against the King of Leinster and his allies. In myth and medieval pseudohistory, as exemplified by the Cogadh Gaedhil re Gallaibh written in the time of Toirdelbach's son, this battle would become the last and greatest between the Irish and the Vikings, and Brian would become the greatest of all Irish kings.