Muiredach Tirech, son of Fiacha Sraibhtine

Fiacha Sraibhtine

Fiacha Sraibhtine, son of Cairbre Lifechair, was, according to medieval Irish legend and historical tradition, a High King of Ireland. On his father's death, Fothad Cairpthech and Fothad Airgthech, sons of Lugaid mac Con, had taken the throne jointly, but within the year Fothad Airgthech killed his...

, was a legendary High King of Ireland

High King of Ireland

The High Kings of Ireland were sometimes historical and sometimes legendary figures who had, or who are claimed to have had, lordship over the whole of Ireland. Medieval and early modern Irish literature portrays an almost unbroken sequence of High Kings, ruling from Tara over a hierarchy of...

 of the fourth 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

Cáelbad

Cáelbad , a descendant of the legendary hero Conall Cernach, was a king of Ulster who became High King of Ireland in the 4th century. He gained the High Kingship by overthrowing Muiredach Tirech, but only lasted a year before he was overthrown by Muiredach's son Eochaid Mugmedon. He married Céindi...

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“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, Seumus MacManus