(Ξοῦθος), a son of Hellen by the nymph Orseis, and a brother of Dorus and Aeolus. He was king of Peloponnesus, and the husband of Creusa, the daughter of Erechtheus, by whom he became the father of Achaeus and Ion (Eurip. Ion. 63, &c.; Apollod. 1.7.3). Others state that after the death of his father Hellen, Xuthus was expelled from Thessaly by his brothers, and went to Athens, where he married the daughter of Erechtheus. After the death of Erechtheus, Xuthus being chosen arbitrator, adjudged the kingdom to his eldest brother-in-law, Cecrops, in consequence of which he was expelled by the other sons of Erechtheus, and settled at Aegialos in Peloponnesus. (Paus. 7.1.2; comp. Hdt. 7.94.)
[L.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890