Fiachrae was an Irish prince, the son of the high king

Eochaid Mugmedón Eochaid Mugmedón () was a semi-legendary Irish king. According to medieval Irish legend and historical tradition, Eochaid was a High King of Ireland, best known as the father of Niall of the Nine Hostages and ancestor of the Uí Néill and Conna ...

(d.362) by his wife

Mongfind Mongfind (or Mongfhionn in modern Irish)—meaning "fair hair" or "white hair"—is a figure from Irish legend. She is said to have been the wife, of apparent Munster origins, of the legendary High King Eochaid Mugmedón and mother of his eldest ...

, sister of

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 t ...

(d.367).Francis J.Byrne, ''Irish Kings and High-Kings'', Table 1 He was ancestor of the Uí Fiachrach dynasties of

Connacht Connacht ( ; ga, Connachta or ), is one of the provinces of Ireland, in the west of Ireland. Until the ninth century it consisted of several independent major Gaelic kingdoms (Uí Fiachrach, Uí Briúin, Uí Maine, Conmhaícne, and Delbh ...

. He lived in the late 4th century. "The Violent Death of Crimthann mac Fidaig and of the Three Sons of Eochaid Muigmedón" gives the story of the sons of Eochaid Mugmedón. According to this saga, his half-brother the high king Niall Noigiallach (d.405) made Fiachrae's full brother Brión his champion and Brion seized the kingship of Connacht. This led to war between Brion and Fiachrae and they fought a battle at Damchluain (near Tuam, Co. Galway). Fiachrae was captured and taken to Tara. However Fiachrae's son Nath Í rallied forces and defeated and slew Brion at a second battle at Damchluain. Fiachrae was now released by Niall and given Brion's position as champion and levier of his hostages and rents. With his brother Ailill, he then went to take hostages from Munster. They defeated Eochaid mac Crimthainn and took loot and hostages. However, Fiachrae was severely wounded and died at Ferrach in Meath on the way home. The hostages of Munster were buried alive with him as a tribute to him.

Notes

References

* Francis J.Byrne, ''Irish Kings and High-Kings'' * ''The Chronology of the Irish Annals'', Daniel P. McCarthy
Dan Wiley's site on the Cycles of the Kings
People from County Roscommon Monarchs from County Mayo 5th-century Irish people {{Ireland-royal-stub