Oceanus (Gr. 'SZKEavos), in Greek mythology, the greatest of rivers and at the same time a divine personification. Never mingling with the sea which it encloses, according to Homer it has neither source nor mouth. On its southern banks, from east to west, dwell the "blameless Aethiopians" in ,perfect happiness, and beyond it on the west, in the realms of eternal night, the "Cimmerians," wrapped in fogs and darkness. Here are the grove of Persephone and the entrance of the underworld. Personified, Oceanus is in Hesiod (Theog. 1 33, 337-37 o) the son of Uranus and Gaea, the husband of Tethys, father of 3000 streams and 4000 ocean nymphs. In Homer he is the origin of all things, even the father of the gods, and the equal in rank of all of them save Zeus. This conception recurs in the theory of Thales, who made water the first principle of all things. The idea of Oceanus as a river flowing unceasingly round the earth, which was regarded as a flat circle, was of long continuance. Euripides was the first among the tragic poets to speak of it as a sea, but Herodotus before him ridiculed the notion of Oceanus as a river as an invention of the poets and described it as the great world sea. As the geographical knowledge of the Greeks extended, the name was applied to the outer sea (especially the Atlantic).
In art, Oceanus was represented as an old man of noble presence and benevolent expression, with the horns of an ox and sometimes crab's claws on his head. His attributes are a pitcher, cornucopiae (", horn of plenty"), rushes, marine animals and a sceptre. On the altar of Pergamum he is depicted taking part in the battle of the giants.
Homer, Iliad, i. 423, xiv. 201, 245, xxi. 196; Odyssey, x. 508, xi. 14; Herodotus ii. 23, iv. 8; Euripides, Orestes, 1376; Caesar, Bell. Gall. iii. 7, iv. 10.
