Myths of Greece and Rome, by Jane Harrison, , at sacred-texts.com
Ares, the war-god brother of Apollo, need not long detain us. He, too, is a northerner, but of Thrace, and, unlike Apollo, he is never really affiliated to Olympus. He is splendid and forceful, but never really respected. Like Apollo, one of his aspects was originally that of a sun-god: as such he appears on the coins of Thrace, and the Homeric Hymn-writer addresses him as "thou that whirlest thy flaming sphere among the courses of the sky"; but he is Helios-Hades, god of the setting, not the rising, sun. As such he is the bringer of death, not only in battle, but by pestilence and famine. In the Œdipus Tyrannos, when the city lies smitten by the plague, the chorus call on Dionysos, god of gladness and life, to banish Ares, him of slaughter and death. They sing:
Sophocles just hits the theological mark. Ares is a god, but he is unhonoured by the orthodox gods, the Olympians.