Muiredach Tirech
Muiredach Tirech, son of Fiacha Sraibhtine, was a legendary High King of Ireland of the 4th century. He gained power by exiling the three Collas, who had killed his father. The Collas later returned and tried to provoke him into trying to kill them. When he didn't, they entered his service and led his armies. He was overthrown by Cáelbad. “In the beginning of the fourth century, Muiredeach Tireach, High-King of Ireland, directed his nephews, the three Collas, to face north and win sword land for themselves. On the ruins of the old kingdom of Uladh they founded a new kingdom -- of Oirghialla -- which was henceforth for nearly a thousand years to play an important part in the history of Northern Ireland, and which was possessed afterwards by their descendants, the MacMahons, O'Hanlons, O'Carrolls, and Maguires.” Story of the Irish Race, Seamus MacManus