Rochad Rigderg ('Red-king') son of Fathemon, was of Ulster. Thrice fifty warriors was his number, and he took possession of a hill fronting the hosts. Finnabair, daughter of Ailill and Medb, perceived that and she went to speak to her mother thereof, even to Medb. "Truly have I loved yonder warrior for a long time," said she; "and it is he is my sweetheart, and mine own choice one in wooing." "An thou hast so loved him, daughter," quoth Ailill and Medb, "sleep with him this night and crave for us a truce of him for the hosts, until he encounters us on the day of the great battle when four of the grand provinces of Erin will meet at Garech and Ilgarech in the battle of the Foray of Cualnge." Rochad son of Fathemon accepted the offer and that night the damsel slept with him.

An Under-king of Munster that was in the camp heard the tale. He went to his people to speak of it. "Yonder maiden was plighted to me on fifteen hostages once long ago," said he; "and it is for this I have now come on this hosting." Now wherever it happened that the seven Under-kings of Munster were, what they all said was that it was for this they were come. "Why," said they, "should we not go to avenge our wife and our honour on the Manè, who are watching and guarding the rear of the army at Imlech in Glendamrach ('Kettle-glen's navel')?"

This was the course they resolved upon. And with their seven divisions of thirty hundreds they arose. Ailill arose with thirty hundred after them. Medb arose with her thirty hundred. The sons of Maga with theirs and the Leinstermen and the Munstermen and the people of Tara. And a mediation was made between them so that each of them sat down near the other and hard by his arms.

Howbeit before the intervention took place, eight hundred very valiant warriors of them had fallen. Finnabair, daughter of Ailill and Medb, had tidings that so great a number of the men of Erin had fallen for her sake and on account of her. And her heart broke in her breast even as a nut, through shame and disgrace, so that Finnabair Slebe ('Finnabair of the Mount') is the name of the place where she fell, died and was buried.

Then said the men of Erin, "White is this battle," said they, "for Rochad son of Fathemon, in that eight hundred exceeding brave warriors fell for his sake and on his account and he himself goes safe and whole to his country and land without blood-shedding or reddening on him." Hence this is the 'White-fight' of Rochad.