Written about 1160 and completed sometime between 1201 and 1224, it contains historical and genealogical poems, mainly on Leinster kings and heroes; mythological and historical accounts of invasions and battles; descriptive prose and verse topographical lists giving the history and etymology of nearly 200 place-names; treatises on bardic and Greek meters; Latin hymns; a version of the hero tale The Cattle Raid of Cooley; and the oldest version of The Tragic Death of the Sons of Usnech
(the legend of Deirdre).
Lavarcham's stories about Naisi, nephew of Conchobar and son of Usnech
, fire her young imagination, and her constant pleas finally persuade Lavarcham to bring him to the house.
Tragic Death of the Sons of Usnech
, The , Irish Oidheadh Chloinne Uisneach.
The tale having the most profound influence on later Irish literature is Tragic Death of the Sons of Usnech