OISIN (pronounced Usheen), reputed to be the son of Finn mac Cumhaill (q.v.), a heroic warrior and bard. He figures to but a small extent in the earlier literature of the Finn cycle, being eclipsed by his father and by his son Oscar. But in the later "Ossianic" literature he is prominent as the narrator of the events through which he claims to have lived. According to the legend, he remained alive after the Battle of Gabhra (Garristown, Co. Dublin) in which Cairbre Liffechair, son of Cormac mac Airt, de stroyed Finn and his followers (A.D. 283), and survived long enough to meet St. Patrick (who arrived in Ireland in A.D. 432) and to tell him the ancient traditions of his youth. This pro longed existence was accounted for by his having been carried off by a fairy maiden to the Happy Otherworld ; a tale not found in any ancient manuscript, but preserved orally, and successfully versified by the 18th-century Irish poet Michael Comyn. In a very valuable prose tract, Agallamh na Senorach ("The Colloquy of the Elders"), Patrick is described as making a circuit of Ire land, with Oisin and his old companion in arms, Caeilte, as ciceroni. The same formula was afterwards adopted in verse, but
with the difference that whereas in the prose narrative the pagan warriors and the saint treat each other with courtesy, in the verses they argue with a petulance often descending to ribaldry on both sides. The poet's name, in the form "Ossian," was popularized by James Macpherson; but his version of the tales and poems is so much manipulated as to be practically a new work.
Agallamh na Sen6rach is published with a translation in O'Grady's Silva Gadelica (189o). For the chief Ossianic poems see the publica tions of the Ossianic Society (1856, 1858) ; also Eoin MacNeill, Duanaire Finn (Irish Texts Society, 1908). See also L. C. Stem, Die Ossianischen Heldenlieder (English Translation in Transactions of the Gaelic Society of Inverness, xxii., p. 257). (R. A. S. M.)