His brother Domhnall (Donnell) was king of Ailech, a district in Donegal and Derry; the royal palace, the ruined masonry of which is still to be seen, being on the summit of a hill Boo ft.
On the death of Domhnall in 911 Niall Glundubh became king of Ailech, and he then attacked and defeated the king of Dalriada at Glarryford, in County Antrim, and the king of Ulidia near Ballymena.
Chief of the clan) on the death of his kinsman Domhnall Boy O'Neill; a dignity from which he was deposed in 1455 by his son Henry, who in 1463 was acknowledged as chief of the Irish kings by Henry VII.
658 Dyfnwal (Domhnall), son of Owain d.
934 Dyfnwal (Domhnall), son of Eoghain (on pilgrimage) d.