in 1259. A feud which was fostered by the Norman de Clares emerged between the descendants of Tadhg (Clann Tadhg) and Brian (Clann Briain) over the kingship of Thomond and lasted until the 14th century with the senior Clann Tadhg eventually being victorious. Family and issue He married Mór, daughter of McNamara, Lord of Uí Coileann (Clann Cullin) and had issue: Tadhg Cael Uisce Ó Briain Brian Ruadh Ó Briain Seonín (Little John) Ó Briain Murtogh Ó Briain Notes References Kings of Thomond