Facts and Events
Mathgamain mac Cennétig was King of Munster from around 970 to his death in 976. He is the elder brother of Brian Bóruma and the ancestor of the McMahon family of County Clare in Western Ireland (Thomond).
Mathgamain was the son of Cennétig mac Lorcáin of the Dál gCais. His father died in 951 and is called king of Tuadmumu in the report of his death, and was probably succeeded by Mathgamain's brother Lachtna, who died in 953 and is not given any distinguishing title at his death.
Mathgamain was captured in 976 by Donnubán mac Cathail, prince of Uí Fidgenti, with whom the Dál gCais were rivaling for territory, and who were currently in alliance with Ivar of Limerick. Donnubán handed him over to his most powerful ally Máel Muad mac Brain, previous king of Munster, who had Mathgamain killed.