The first king of Elis. (Paus. v. 1. § 2.) He was a son of Zeus and Protogeneia, the daughter of Deucalion (Apollod. i. 7. § 2; Hygin. Fab. 155), and was married to Calyce, by whom he begot Endymion. According to some accounts Endymion was himself a son of Zeus and first king of Elis. (Apollod. i. 7. § 5.) Other traditions again made Aëthlius a son of Aeolus, who was called by the name of Zeus. (Paus. v. 8. § 1.)