Cormac son of Cuilennan
also Cormac II mac Cuilennáin
836-908

Scholar, warrior, king, and bishop, Cormac mac Cuilennan is one of the more interesting figures of Irish history. A member of the Eoghanacht clan of southern Ireland, Cormac was bishop of Lis Móir, only to unexpectedly ascended to the throne of Cashel, becoming King of Munster in 900 AD.

Now, his wife is recorded as Lady Gormley of the Uí Niall clan, who had the strange fate of marrying two other kings after him--the king of Leinster, and the ard rí Niall Black-Knee. At the same time, Cormac was bishop of Cashel. This creates an interesting "problem"--if he was bishop and king, how could he be married? for an Irish king must be married and produce offspring.

What one must understand is that the Irish church, celibacy was not the rule--indeed, not even the norm--in the middle ages. Abbeys (and I believe even bishoprics) could and would be passed on from father to son. It wasn't until 1215 that the Roman Catholic Church truly made celibacy an issue, and it wasn't strictly enforced until the Council of Trent in the sixteenth century. Hense, it was entirely kosher to have a married bishop in Ireland. What is stranger is that he was a bishop and king. He had studied with Irish monks as a youth, became a priest and was ordained bishop of Lis Móir. In 900, on acount of his bloodlines, he became Cormac II, king of Cashel, and thus both the temporal and spiritual leader of Leth Moga--southern Ireland.

Cormac is best known as the author of Cormac's Glossary, an encyclopedia of Irish folklore. It was his attempt to define various Irish terms, customs, holidays, beliefs, and deities. While his effort is certainly admirable, his etymologies are incorrect, based more on folklore than on scholarship. (But then, this was the late ninth century, and allowances must be made.)

As king, Cormac had to fight off two invasions of Munster by the ard rí Flann and the kings of Leinster and Connacht. He was successful fighting the first attact, but caused the second attack when, at the instigation of Flaherty, Abbot of Inniscathay, he tried to extract tribute from Leinster, and even considered becoming ard righ. While this may have produced an interesting theocracy--a married priest-king with more than a passing interest in Ireland's pagan past--this was not to be. Flann and Ceorbhall, king of Leinster, attacked Munster, and Cormac was killed in battle in 908.

Sources:
The Catholic Encyclopedia
Caithreim Ceallachain Caisil