Uí Briúin

Uí Briúin were a Connachta dynasty whose eponymous ancestor was Brión (Brian), son of Eochaid Mugmedón and step‐brother of Niall Noígiallach. This reputed relationship was used in early Ireland to underpin perceived connections between the Uí Néill and the Connachta, the two most powerful groupings in Leth Cuinn. The Uí Briúin and their descendants, the Síl Muiredaig and the Uí Chonchobair, controlled the kingship of Connacht for most of the pre‐Norman period; within their lands was the important centre of Crúachain (Rathcroghan), the western equivalent of Tara. Subgroupings of the Uí Briúin include Uí Briúin Aí of central Roscommon, Uí Briúin Seóla east of Lough Corrib, Uí Briúin Umaill of Clew Bay, and Uí Briúin Bréifne in modern Leitrim and Cavan. Genealogical connections between these various groupings often depend on otherwise unattested sons of Brión, and many appear to represent falsification of pedigrees by emerging dynasties in Connacht.

Catherine Swift