Ferchu Longsech (the Exile), although of the Connachtmen, was engaged in battle and plunder with Ailill and Medb. From the day these came to the kingship, there never was a time that he fared to their camp or took part in their expeditions or shared in their straits or their needs or their hardships, but he was ever at their heels, pillaging and plundering their borders and land.

At that time he sojourned in the eastern part of Mag Ai. Twelve men was his muster. He learned that a single man checked and stopped four of the five grand provinces of Erin from Monday at Summer's end till the beginning of Spring, slaying a man on the ford every one of those days and a hundred warriors every night. He weighed his plan privily with his people. "What better plan could we devise?" quoth he, "than to go and attack yonder man that checketh and stoppeth four of the five grand provinces of Erin, and bring his head and his weapons with us to Ailill and Medb? However great the injuries and wrongs we have done to Ailill and Medb, we shall obtain our peace therefor, if only that man fall by our hand."

Now this was the resolve they took, and they proceeded to where Cuchulain was. And when they came, it was not fair fight nor combat with one they vouchsafed him, but at one and the same time the twelve men fell upon him. Cuchulain turned on them, and straightway he smote off their twelve heads. And he set up twelve stones in the earth for them, and he put the head of each one of them on its stone and he likewise put Ferchu Longsech's head on its stone. Hence Cinnit Ferchon Longsig is henceforth the name of the place where Ferchu Longsech left his head, to wit, Cenn-aitt Ferchon ('the Head-place of Ferchu').