The Dal Fiachrach Suighe (Seed of Fiachra Suighe) were an Irish

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

 lineage claiming descent from Fiachra Suighe, the youngest of six sons of Fedlimid Rechtmar

Fedlimid Rechtmar

Fedlimid Rechtmar or Rechtaid son of Tuathal Techtmar, was, according to medieval Irish legend and historical tradition, a High King of Ireland. His mother was Báine, daughter of Scál. He took power after killing his predecessor, and his father's killer, Mal mac Rochride...

. His oldest brother was the legendary High King

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...

 Conn Cétchathach

Conn of the Hundred Battles

Conn Cétchathach , son of Fedlimid Rechtmar, was, according to medieval Irish legend and historical tradition, a High King of Ireland, and the ancestor of the Connachta, and, through his descendant Niall Noígiallach, the Uí Néill dynasties, which dominated Ireland in the early middle ages, and...

. Fiachra's great-great-great-great grandsons, the four sons of Art Corb, were expelled from Tara, a story told in The Expulsion of the Déisi

The Expulsion of the Déisi

The Expulsion of the Déisi is a medieval Irish narrative of the Cycles of the Kings. It dates approximately to the 8th century, but survives only in manuscripts of a much later date. It describes the fictional history of the Déisi, a group that had gained political power in parts of Ireland during...

. One group, led by Eochaid Allmhuir, settled in Dyfed

Dyfed

Dyfed is a preserved county of Wales. It was created on 1 April 1974 under the terms of the Local Government Act 1972, and covered approximately the same geographic extent as the ancient Principality of Deheubarth, although excluding the Gower Peninsula and the area west of the River Tawe...

 c. 270, while the second group eventually settled among the Déisi

Déisi

The Déisi were a class of peoples in ancient and medieval Ireland. The term is Old Irish, and derives from the word déis, meaning "vassal" or "subject"; in its original sense, it designated groups who were vassals or rent-payers to a landowner. Later, it became a proper name for certain septs and...

 of south Munster

Munster

Munster is one of the Provinces of Ireland situated in the south of Ireland. In Ancient Ireland, it was one of the fifths ruled by a "king of over-kings" . Following the Norman invasion of Ireland, the ancient kingdoms were shired into a number of counties for administrative and judicial purposes...

. These events have been tied to Irish pirate raids all over the west coast of Roman Britain

Roman Britain

Roman Britain was the part of the island of Great Britain controlled by the Roman Empire from AD 43 until ca. AD 410.The Romans referred to the imperial province as Britannia, which eventually comprised all of the island of Great Britain south of the fluid frontier with Caledonia...

 in the 4th and 5th centuries and to the foundation of the Irish kingdoms of Dyfed

Dyfed

Dyfed is a preserved county of Wales. It was created on 1 April 1974 under the terms of the Local Government Act 1972, and covered approximately the same geographic extent as the ancient Principality of Deheubarth, although excluding the Gower Peninsula and the area west of the River Tawe...

, Brecon

Brecon

Brecon is a long-established market town and community in southern Powys, Mid Wales, with a population of 7,901. It was the county town of the historic county of Brecknockshire; although its role as such was eclipsed with the formation of Powys, it remains an important local centre...

 and Cornwall

Cornwall

Cornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of...

around 400.