The Cattle-Raid of Cooley is the central epic of the Ulster cycle. Queen Medb of Connaught gathers an army in order to gain possession of the most famous bull in Ireland, which is the property of Daire, a chieftain of Ulster. Because the men of Ulster are afflicted by a debilitating curse, the seventeen-year-old Cuchulain must defend Ulster single-handedly.

 The battle between Cuchulain and his friend Ferdiad is one of the most famous passages in early Irish literature.