In it the Three Collas—Colla Menn, Colla Da Crioch, and Colla Uais—were the sons of Eocaidh Doimlén. It is from them that the Airgíalla are said to descend, branching off from the rest of the Connachta. The Northern and Southern Uí Néill dynasties are claimed to descend from Eocaidh's brother, Fiacha Sraibhtine. According to the story the Collas were told by Fiacha's son, Muiredach Tirech, the High King of Ireland, to conquer land of their own to pass on to their descendants, directing them to wage war on the Ulaid to avenge a slight against their great-grandfather Cormac mac Airt.