In Greek mythology, Oceanus (/oʊˈsiː.ə.nəs/; Greek: Ὠκεανός, also Ὠγενός, Ὤγενος, or Ὠγήν) was a Titan son of Uranus and Gaia, the husband of his sister the Titan Tethys, and the father of the river gods and the Oceanids, as well as being the great river which encircled the entire world.
When Cronus, the youngest of the Titans, overthrew his father Uranus, thereby becoming the ruler of the cosmos, according to Hesiod, none of the other Titans participated in the attack on Uranus. However, according to the mythographer Apollodorus, all the Titans—except Oceanus—attacked Uranus. Proclus, in his commentary on Plato's Timaeus, quotes several lines of a poem (probably Orphic) which has an angry Oceanus brooding aloud as to whether he should join Cronus and the other Titans in the attack on Uranus. And, according to Proclus, Oceanus did not in fact take part in the attack.
Hades (/ˈheɪdiːz/; Greek: ᾍδης Hádēs; Ἅιδης Háidēs), in the ancient Greek religion and myth, is the god of the dead and the king of the underworld, with which his name became synonymous. Hades was the eldest son of Cronus and Rhea, although the last son regurgitated by his father. He and his brothers, Zeus and Poseidon, defeated their father's generation of gods, the Titans, and claimed rulership over the cosmos. Hades received the underworld, Zeus the sky, and Poseidon the sea, with the solid earth, long the province of Gaia, available to all three concurrently. Hades was often portrayed with his three-headed guard dog Cerberus.
The Etruscan god Aita and the Roman gods Dis Pater and Orcus were eventually taken as equivalent to Hades and merged into Pluto, a Latinization of Plouton (Greek: Πλούτων, Ploútōn), itself a euphemistic title often given to Hades.