Eldest son. He became King of Connacht having resigned the monarchy of all Ireland in favor of his younger brother, Niall.208

The Connachta proper claimed descent from Brión, Fiachra and Ailill, the brothers of Niall Naoighiallach and gave their name to the province of Connacht. Brión's descendants, the Uí Briúin included the royal house of O'Conor and several other Connacht families.205