(Ἀέθλιος), the first king of Elis. (Paus. 5.1.2.) He was a son of Zeus and Protogeneia, the daughter of Deucalion (Apollod. 1.7.2; Hyg. 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. 1.7.5.) Other traditions again made Aethlius a son of Aeolus, who was called by the name of Zeus. (Paus. 5.8.1.)
[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