Xuthus

In Greek mythology, Xuthus (Classical Greek ) was a son of Hellen and Orseis and founder (through his sons) of the Achaean and Ionian nations. He had two sons by Creusa: Ion and Achaeus and a daughter named Diomede. According to Hesiod's (probably) "Eoiae" (Greek : Ηοίαι) or "Catalogue of Women" on the origin of the Greeks, Pandora (named after her grandmother Pandora, sister of Hellen and daughter of Deukalion and Pyrrha) together with Zeus had three sons: Graecus, Magnetas and Macedon who together with Hellen's three sons Dorus, Xuthus (with his sons Ion and Achaeus) and Aeolos, comprised the set of progenitors of the ancient tribes that formed the Greek/Hellenic nation.
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[Greek] The son of Hellen and mythical ancestor of the Achaeans and Ionians. The Achaeans were a people of an ancient region in the northern Peloponnisos, Greece. The region where they lived was known as Achaea.