Fenian cycle,

    also called FIONN CYCLE, or OSSIANIC CYCLE, in Irish Gaelic literature, tales and
ballads centring on the deeds of the legendary Finn MacCumhaill (MacCool) and his war
band, the Fianna Éireann. An elite volunteer corps of warriors and huntsmen, skilled in
poetry, the Fianna flourished under the reign of Cormac mac Airt in the 3rd century AD.
The long-established Fenian lore attained greatest popularity about 1200, when the cycle's
outstanding story, The Colloquy of the Old Men, was written down. Other earlier tales
were recorded in manuscripts such as The Book of the Dun Cow (c. 1100) and The Book
of Leinster (c. 1160). The Fenian cycle remains a vital part of Irish folklore and contains
many of the best-loved folk tales of the country. See also Dun Cow, The Book of the;
Leinster, The Book of.

    An early tale, The Boyish Exploits of Finn (Macgnímartha Finn), tells how, after
Cumhaill (Cool), chief of the Fianna, is killed, his posthumous son is reared secretly in a
forest and earns the name Finn ("The Fair") by his exploits. He grows up to triumph over
his father's slayer, Goll MacMorna, to become head of the Fianna, which later includes his
son Oisín (Ossian), the poet, his grandson Oscar, the handsome Diarmaid (Dermot), and his
former clan enemy Goll MacMorna. According to legend, Finn was a descendant of the
Druids. He was wise and sensitive to nature and became a popular hero as a kingly figure in
the 7th century. The other tales deal with the group's rise and fall. Its disintegration begins
when Diarmaid elopes with Gráinne (Grace), a king's daughter whom Finn, as an old man,
wishes to marry. Later, when Diarmaid is wounded, Finn lets him die for lack of water. The
king and people finally turn against the overbearing Fianna, a conflict that culminates in the
Battle of Gabhra, in which the Fianna is destroyed. Oscar is killed in battle; Oisín survives
but is lured away by a fairy princess to Tír na nÓg (the "Land of Youth"). (See also
Interrogation of the Old Men, The.) Related to the Fenian sagas is a series of tales
concerning Cormac mac Airt, his grandfather Conn of the Hundred Battles, and his son
Cairbré of the Liffey.