Irish title of a Fenian Cycle narrative known in English as ‘The Cause of the Battle of Cnucha’, found in the 12th-century Book of the Dun Cow [Lebor na hUidre]. The action focuses on the death of Cumhall, father of Fionn mac Cumhaill, and explains the long-standing enmity between the rival clans Baíscne, led first by Cumhall and later by Fionn, and Clan Morna, led by Goll mac Morna. Sometimes Conn Cétchathach [of the Hundred Battles] takes Goll's place in the rivalry. The Cnucha of the title, later called Castle Knock or Castleknock, is today located on the grounds of Castleknock College near Phoenix Park, Dublin.
See W. H. Hennessy, ‘The Battle of Cnucha’, Revue Celtique, 2 (1873), 86–93.