Oidheadh Chloinne Uisneach (The Tragic Death of the Sons of Usnech). Fifteenth Century AD (c AD 1160), as early as Eighth/Ninth Century AD (First Century AD).

Oidheadh Chloinne Uisneach (The Tragic Death of the Sons of Usnech). Fifteenth Century AD (c AD 1160), as early as Eighth/Ninth Century AD (First Century AD):

Graham, William. Deirdre and the Sons of Uisneach: a Scoto-Irish romance of the first century AD. Edinburgh: J Gardner Hitt, 1908.
https://ia902703.us.archive.org/2/items/deirdresonsofuis00grahuoft/deirdresonsofuis00grahuoft.pdf