The tragic story of Cormac Connloinges, son of Conchobar mac Nessa, was last edited in 1900. The present edition by Professor Gregory Toner reflects the enormous advances since made in Irish scholarship. A lengthy introduction, translation, and full critical apparatus accompany the edition. The editor dates the work to the early twelfth century. Moreover, he presents a very persuasive argument for a Clonmacnoise provenance, and for use on the part of the author of the monastery's extensive library, then comprising, among other manuscripts, Lebor na Uidre (The Book of the Dun Cow).