From Smith's Dictionary of Greek and Roman Biography and Mythology

AETHLIUS

the first king of Elis. He was a son of Zeus and Protogeneia, the daughter of Deucalion (Apollodorus i), 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. (Apollodorus i) Other traditions again made Aethlius a son of Aeolus, who was called by the name of Zeus.