Toirdhealbhach Mór Ó Briain

Toirdhealbhach Mór Ó Briain (c. 1250–1306), son of Tadhg Cael Uisce, made himself King of Thomond by deposing his uncle Brian Ruadh in 1276. When Brian returned with Thomas de Clare's backing, he rallied his cousin William de Burgh and overthrew their army in 1277.

His long struggle with de Clare, who then backed Brian's son Donnchadh until he drowned in 1284, became the subject of the epic Caithréim Thoirdhealbhaigh. He ruled until his death in 1306, when his son Donnchadh succeeded him.