Four branches of the Ciarraige were known to be located in Connacht. Ciarraige Óic Bethra were located in what was then the kingdom of Aidhne (now south County Galway), where they were one of the three peoples living in Aidhne prior to the arrival of the Uí Fiachrach in the 6th century.
Ciarraige Aí, Ciarraige Airtig and Ciarraighe Locha na nÁirne, were located further north, adjacent to each other along the east County Mayo/west-central County Roscommon area. They were thought to have once formed a single over-kingdom which was broken up by the rise of the Uí Briúin in the 8th and 9th centuries.
In 2000, Nollaig Ó Muraíle wrote of them as follows (p. 165):
"The most notable of the latter are Ciarraige Aí, also called Ciarraige Maige Aí, who obviously derive their designation from the great central plain of Roscommon, Mag nAí, in which the ancient 'capital' of Connacht, Cruachu, stood. Their settlement in contiguity to such a significant royal site must surely bespeak their possessing a considerable status at some stage just over the historical horizon. They first appear in the annals towards the close of the eighth century when, in 796, the Annals of Ulster record the death of Duinechaid ua Daire, whom it describes as 'dux Ciarraide'; this is expanded by the Four Masters to 'tighearna Ciarraighe Aí' and the latter also tells of the death in the same year of Fogartach mac Cathail who is termed 'tighearna Maighe Aí' ... The title used by the Four Masters ('lord of Mag nAí') is indicitive of the struggle for control of this crucial territory between the Ciarraige of the area and the rising dynastic power of the Uí Briúin."