King of Tara and antagonist of Cúchulainn in the Ulster Cycle, apparently because of a rivalry over Conchobar's daughter. Fedelm Noíchrothach or Noíchride, whom he marries. Cúchulainn disdains Emer's older sister Fial (2) because of her relationship with Cairbre Nia Fer. Cúchulainn makes short work of him at Ros na Rígh. To avenge this killing Erc (1) also engages Cúchulainn in battle. Cairbre is celebrated for his twelve daughters; his full patronymic is mac Rosa Ruaid. Cairbre's attributed brother is Find File, mythical king of Leinster.