They crossed the Shannon near Athlone and, marching through the province of Meath, arrived at the borders of Cualnge. Fortunately for the invaders, the expedition took place while the Ulstermen lay prostrate in their cess, or “Pains,” a mysterious state of debility or torpor which was inflicted on them periodically in consequence of an ancient curse laid upon Conchobar and the warriors of Ulster as a punishment for a wrong done to the goddess Macha. This strange malady, resembling the couvade among certain savage nations, ordinarily lasted five days and four nights, but on this occasion the Ulstermen were prostrate from the beginning of November till the beginning of February. During all that time the burden of defending the province fell on the shoulders of the youthful champion Cuchulain, who had in his particular charge the plain of Murthemne, the nearest district to Cualnge, the goal of the expedition. For Cuchulain and his father Sualtaim were alone exempt from the curse and the “Pains” which had befallen the remainder of the champions of Ulster.
The Connacht host had not proceeded far when they came upon evidence of some mighty force that opposed them. In answer to the inquiries of Ailill and Medb, Fergus explains that it is Cuchulain who disputes their further advance, and, as evidence of the superhuman strength and prowess of the Ulster youth, then in the seventeenth year of his age, the Ulster exiles recount the mighty deeds he had performed in his boyhood, chief among which is the tale according to which, as eric for the killing of the hound of Culann the Smith, the boy-hero Setanta assumed the station and the name which ever after clung to him of Cuchulain, “the Hound of Culann.”
Cuchulain agrees to allow the Connacht host to continue their march on condition that every day they send one of their champions to meet him in single combat. When he shall have killed his opponent, the host shall halt and pitch camp until the following morning. Medb agrees to abide by these terms. In each of the contests which ensue, the heroic youth is victorious and slays many of the most celebrated warriors on the side of Connacht. The severest of all these single combats was the one in which he had as opponent his former friend and foster-brother Ferdiad. At the end of a four days’ battle, in which both adversaries exhibited astounding deeds of valour, Ferdiad fell by the hands of Cuchulain.
Impatient at these delays, Medb broke the sacred laws of ancient Irish chivalry and led her army into Ulster, overrunning the province, pillaging and burning as she went, even up to the walls of Emain Macha, the residence of Conchobar, and finally took possession of the Brown Bull of Cualnge.