His literary fame also has its memorials.

His Rule is contained in a poem of fourteen stanzas, written in the most pure and ancient style of Gaedhilic, of which, as well as of many other languages, the illustrious Cormac was so profound a master.

This Rule is general in several of its inculcations; but it appears to have been written particularly as an instruction to a priest, for the moral and spiritual direction of himself and his flock.

He was also skilled in the Ogham writings, as may be gathered from a poem written by a contemporary, who, in paying compliments to many of the Irish kings and chiefs, addresses the following stanza to Cormac:-- "Cormac of Cashel, with his champions, Munster is his,--may he long enjoy it! Around the King of _Raith-Bicli_ are cultivated The letters and the trees." The death of Cormac is thus pathetically deplored by Dallan, son of Mor:-- "The bishop, the soul's director, the renowned, illustrious doctor, King of Caiseal, King of Farnumha: O God! alas for Cormac!" Flann's last years were disturbed by domestic dissensions.

His sons, Donough and Conor, both rebelled against him; but Nial Glundubh (of the black knee), a northern Hy-Nial chief, led an army against them, and compelled them to give hostages to their father.