Demmán mac Cairell

Who was Demmán mac Cairell?

Demmán mac Cairill was king of the Dal Fiatach, and high-king of Ulaid. He was the son of Cairell mac Muiredaig Muinderg, a previous Ulster king and brother of Báetán mac Cairill. He ruled the Dal Fiatach and Ulaid from 557 to 572.

According to the genealogies, he was fostered by a certain Domangart mac Predae, possibly Domangart Réti, King of Dál Riata. He acquired the kingship of Ulaid by defeating and slaying Fergnae mac Oengusso Ibdaig at the Battle of Druim Cleithe and had the support of the Uí Echach nÁrda. He himself was slain by the shepherds of Boirenn.

He was married to Garbae ingine Néilléne of the Cenél nEógain. He had five sons including Fiachnae mac Demmáin, a later king of Ulster. His descendants the Clan Demmáin went on to monopolize the kingship of the Dal Fiatach.