Concerning The Tain

Ireland's most exciting saga is, undoubtedly, Tain Bo Cuailgne ( The
Cattle Raid of Cooley ), the centrepiece of the Ulster cycle of Heroic
Tales.
Normally referred to as "The Tain", it deals with the conflict between
the forces of Connacht and Ulster for possession of a prize bull.
The events of the Tain are estimated to have taken place in Ireland
approximately 500 B.C. The earliest written version of the Tain known
to us is contained in the Book of the Dun Cow, which dates from the 12th
century. Before this the story was kept alive by storytellers.
Two other manuscript versions are also available; the 12th century Book
of Leinster and the 14th century Yellow Book of Lecan. The Tain, as
Ireland's equivalent of the Aeneid, has long intrigued historians, academics
and writers.