In the thirty-ninth year of his reign, one of his eyes was thrust out by a spear, and he retired in consequence to one of those peaceful abodes of learning which were so carefully fostered in ancient Erinn.

The high-minded nobility of this people is manifest notably in the law which required that the king should have no personal blemish; and in obedience to this law, Cormac vacated the throne.

He died A.D.266, at Cleiteach, near Stackallen Bridge, on the south bank of the Boyne.

It is said that he was choked by a salmon bone, and that this happened through the contrivances of the druids, who wished to avenge themselves on him for his rejection of their superstitions.
This reign was made more remarkable by the exploits of his son-in-law, the famous Finn Mac Cumhaill (pronounced "coole").

Finn was famous both as a poet and warrior.