Kings of Airgíalla

Between the sixth and sixteenth centuries, the Kingdom of Airgíalla (Anglicized as Oriel) was one of the three major kingdoms that formed what is now the province of Ulster. The others were In Tuisceairt to the north and west, and Ulaid to the east.

Originally a confederation comprising some nine different, mainly unrelated peoples, its kings were from a number of different dynasties. There were times when there was no one supreme king of Airgíalla, with two or more kings ruling portions of the kingdom. They have not been included on this list.

...
Wikipedia