Eochaid mac Fiachnai

Who was Eochaid mac Fiachnai?

Eochaid mac Fiachnai was a Dal Fiatach king of Ulaid, which is now Ulster, Ireland. He was the son of Fiachnae mac Áedo Róin, a previous king. He ruled from 790 to 810.

Eochaid first appears in the annals in 776. In that year he gave his support to Tommaltach mac Indrechtaig in a civil war among the rival Dal nAraide family. They defeated and slew the incumbent king Cináed Ciarrge mac Cathussaig and his ally, Dúngal king of the Uí Tuirtri at the Battle of Drong.

His father had restored the fortunes of the Dal Fiatach dynasty but upon his death a succession struggle broke out. Eochaid was challenged for the kingship by his kinsmen Tommaltach mac Cathail. Tommaltach was the great grandson of Óengus, son of Máel Cobo mac Fiachnai king of Ulaid and this branch threatened to be excluded from the throne. Tommaltach was defeated and slain in battle by Eochaid. However Tommlatach's branch of the family remained based in Leth Cathail-"Cathal's Half" in southern modern County Down.

Tommaltach mac Indrechtaig of Dal nAraide had profited by the civil war among the Dal Fiatach to acquire the throne of all Ulaid. He died the next year in 790 and in that year the annals also record a slaughter of the Dal Fiatach by the Dál nAraidi. Whether this occurred before or after Tommaltach's death is uncertain. Eochaid became King of Ulaid in 790.