Hellen, in Greek mythology, king of Phthia (at the northern end of the Gulf of Euboea), son of Deucalion (the Greek Noah) and Pyrrha and grandson of the Titan Prometheus; he was the eponymous ancestor of all true Greeks, called Hellenes in his honour. The Hellenes consisted of the Aeolians, Dorians, Ionians, and Achaeans, traditionally descended from and named for Hellen’s sons, Aeolus and Dorus, and his grandsons (by his third son, Xuthus), Ion and Achaeus.