Cormac mac Cuilennáin

Cormac mac Cuilennáin (died 13 September 908) was an Irish bishop and was king of Munster from 902 until his death at the Battle of Bellaghmoon. He was killed fighting in Leinster, probably attempting to restore the fortunes of the kings of Munster by reimposing authority over that province.

Cormac was regarded as a saintly figure after his death, and his shrine at Castledermot, County Kildare, was said to be the site of miracles. He was reputed to be a great scholar, being credited with the authorship of the Sanas Cormaic (Cormac's Glossary), and the now-lost Psalter of Cashel, among other works. The reliability of some of the traditions concerning Cormac is doubtful.

The Ireland of Cormac's time was divided into a small kingdoms, or túatha, perhaps 150 in all, on average around 500 square kilometres in area with a population of some 3000. In theory, but not in practice, each tuath had its own king, bishop and court. Variations in size and power were very considerable. Groups of tuatha were dominated by one of their number, whose king was their collective ruler. Above these stood the four great provincial kingships whose names survive in the provinces of Ireland of today: Connacht, Leinster, Ulster and Cormac's Munster. To these can be added the kings of the northern and southern Uí Néill. These last provided were the High Kings of Ireland, kings whose authority was an increasingly obvious political fact in Ireland of the 8th and 9th centuries. In Cormac's time the High Kingship was held by Flann Sinna of the Clann Cholmáin branch of the southern Uí Néill. In addition to these native Irish kings, Ireland, during the Viking Age, had seen Scandinavian and Norse-Gael kings establish themselves along the coasts. The destruction of Viking settlements on the northern coasts by Flann's predecessor Áed Findliath, followed by a much internal dissension, had weakened the Vikings, who were expelled from Dublin by Flann's allies in the year that Cormac became king in Munster.

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