Original owner of Donn Cuailnge, the Brown Bull of Cuailnge or Cooley, in Táin Bó Cuailnge [Cattle Raid of Cooley]. After promising Donn Cuailnge to Medb of Connacht, Dáire overheard messengers, drunk at a feast, say he was a fool to hand over the bull. When Dáire then refused, Medb and her armies advanced into Ulster to take Donn Cuailnge by force. In a sense, this otherwise obscure Ulster chief set in motion the war in Ireland's greatest epic. See also FIACHNA MAC DÁIRI, whose catching of the ‘water worm’ leads to Donn Cuailnge's conception.