Cairell mac Muiredaig Muinderg
Cairell mac Muiredaig Muinderg also Cairell Coscrach was a king of Ulaid from the Dal Fiatach. He was the son of Muiredach Muinderg mac Forggo and brother of Eochaid mac Muiredaig Muinderg, previous kings.
His accession date is given in the Annals of Tigernach in 509 and the accession of his successor in 532 This annal gives him a reign of 509-532
In the period following the destruction of Emain Macha after 450, Ulidia underwent a recuperation in which the Dal Fiatach emerge as the overlords with his father Muiredach as the first historical king. In 496/498 the annals record the storming of Dún Lethglaise which may be connected with the rise of Dal Fiatach in this area which was to become their power base.
The Tripartite Life of St. Patrick has a story that Saint Patrick cursed the descendants of his brother Eochaid and gave his blessing to the descendants of Cairell. Cairell's descendants did monopolize the kingship. His known sons were Demmán mac Cairill and Báetán mac Cairill, both kings of Ulaid.