TheDal Fiachrach Suighe (English:Seed of Fiachra Suighe) were anIrish lineage claiming descent fromFiachra Suighe (also speltFiacha Suidhe), the youngest of six sons ofFedlimid Rechtmar. His oldest brother was the legendaryHigh KingConn Cétchathach. They are the ancestors of theDéisi Muman and theDéisi Tuisceart (later known as theDál gCais).
Fiachra's great-great-great-great grandsons, the four sons of Art Corb, were expelled fromTara, a story told inThe Expulsion of the Déisi.[1] One group, led by Eochaid Allmhuir, settled inDyfed c. 270,[2][3] while the second group eventually settled among theDéisi of southMunster. These events have been tied to Irish pirate raids all over the west coast ofRoman Britain in the 4th and 5th centuries and to the foundation of the Irish kingdoms ofDyfed,Brecon andCornwall around 400.