Crimthann mac Fidaig

Crimthann Mór, son of Fidach, also written Crimthand Mór, was a semi-mythological king of Munster and High King of Ireland of the 4th century. He gained territory in Britain and Gaul, but died poisoned by his sister Mongfind. It is possible that he was also recognized as king of Scotland. This Crimthann is to be distinguished from two previous High Kings of Ireland of the same name, two Kings of Leinster, and another King of Munster, among others. Importantly, he is included in the Baile Chuinn Chétchathaig (summary), and is thus the last High King of Ireland from Munster until Brian Bóruma, over six hundred years later.