Irish title for an Old Irish narrative known in English as The Adventure of Cormac or Cormac's Adventure in the Land of Promise [Tír Tairngire]. Texts survive in the Book of Ballymote, the Book of Fermoy, and the Yellow Book of Lecan. The protagonist is Cormac mac Airt, a legendary king of Ireland and grandson of Conn Cétchathach [of the Hundred Battles].
One day at dawn, as Cormac mac Airt is walking the rampart at Tara, he espies a warrior approaching who carries a branch with three golden apples. When he learns that the branch, when shaken, will produce a marvellous music that casts sleep upon all who hear it, Cormac asks to have it. The strange warrior agrees, asking in return the promise of three wishes, to which Cormac agrees. A year passes before the warrior asks his first wish, Cormac's daughter Ailbe, which Cormac grants. A month later he asks for Cairbre Lifechair, Cormac's son, and again the father grants it. A third time the warrior asks for Eithne (probably Eithne Tháebfhota), Cormac's wife. This Cormac will not allow; he pursues the warrior and his captives, including Eithne, until lost in a magical mist that falls upon the plain. After many adventures and sights Cormac comes to a castle where he is hospitably entertained by a handsome warrior. A pig is put on the spit for roasting as host and guests begin a unique storytelling contest. The pig cannot be cooked unless a truth is told for each quarter. When Cormac has to tell the fourth story, he relates how first his daughter, then his son, and finally his wife have been taken from him. At this the pig is found to be ready. Cormac protests that he usually dines with a company of fifty. The warrior sings a lullaby, putting Cormac to sleep; and when he awakes he finds fifty warriors around him, as well as his daughter, son, and wife.
The handsome host is given a golden cup whose craftsmanship startles Cormac. More importantly, it is a cup of truth, as the host demonstrates. He tells three lies and the cup breaks into three parts. He then tells Cormac that Eithne has lain with no man since she left Tara, nor has Ailbe, and that Cairbre has lain with no woman. The testimonies fuse the cup together, making it whole. At this the host reveals his true identity: he is Manannán mac Lir, the sea-god; he is also the mysterious warrior who led them into the Land of the Living. He allows Cormac to keep the magical branch and cup for his lifetime, but that after that they must leave Ireland. Next morning Cormac, Eithne, Ailbe, and Cairbre find themselves at Tara again. Cormac uses the cup to test falsehood during his reign, but at his death it is not seen in Ireland again.
See translation by Whitley Stokes, Irische Texte, 3 (1) (Leipzig, 1891), 211–16; repr. in T. P. Cross (ed.), Ancient Irish Tales (New York, 1936), 503–7; Vernam Hull, ‘Echtra Cormaic maic Airt, “The Adventure of Cormac mac Airt”’, PMLA 64 (1949), 871–83. Several commentators have noted the parallel between Cormac's visit to the Land of the Living and Percevel's visit to Grail Castle. The motif of the testing cup of truth may be traced as far away as India; see Myles Dillon, ‘The Hindu Act of Truth in Celtic Tradition’, Modern Philology, 45 (1947), 137–40.