The tragic Ulster Cycle heroine who eloped with Naoise is Deirdre.
In the traditional story, Deirdre is prophesied to bring sorrow to Ulster. King Conchobar plans to marry her, but she falls in love with Naoise, one of the sons of Uisneach. With his brothers Ardan and Ainnle, she flees with Naoise to Scotland.
Their exile is short-lived. Conchobar lures the group back to Ulster under a promise of safe conduct, but Naoise and his brothers are killed. Deirdre is forced to become Conchobar’s wife and later dies by throwing herself from a chariot.
Deirdre is sometimes called Deirdre of the Sorrows, especially in later retellings and J. M. Synge’s unfinished play. She is often confused with other famous Irish mythological women, such as Medb, Emer, and Gráinne, but none of those figures is Naoise’s eloping lover.