Tigernán Ua Ruairc

Who was Tigernán Ua Ruairc?

Tighearnán Mór Ua Ruairc, anglicised as Tiernán O'Rourke ruled the Kingdom of Bréifne as the 19th king in its Ua Ruairc dynasty. He was a descendant of Ui Riagain, and one of the provincial kings in Ireland in the twelfth century, constantly expanding his kingdom through shifting alliances, of which the most long-standing was with Toirdelbach Ua Conchobair King of Connacht and High King of Ireland, and subsequently his son and successor Ruaidhri Ua Conchobair. He is known for his role in the expulsion of Diarmait Mac Murchada, King of Leinster, from Ireland in 1166. Mac Murchada's subsequent recruitment of Marcher Lords to assist him in the recovery of his Kingdom of Leinster ultimately led to the Norman Invasion of Ireland.