Tethys was a greek titaness and also a poetic word for sea in Greek Mythology.
Tethys played no active part in Greek mythology, the only early story concerning Tethys, is what Homer has Hera briefly relate in the Iliad's Deception of Zeus passage. There, Hera says that, when Zeus was in the process of deposing Cronus, she was given by her mother Rhea to Tethys and Oceanus, for safekeeping, and that they "lovingly nursed and cherished me in their halls". Hera relates this while dissembling that she is on her way to visit Oceanus and Tethys, in hopes of reconciling her foster parents, who angry with each other, are no longer having sexual relations.
Originally Oceanus' consort, at a later time Tethys, came to be identified with the sea, and In Hellenistic and Roman poetry, Tethys' name came to be used as a poetic term for the sea. The only other story involving Tethys is an apparently late astral myth concerning the polar constellation Ursa Major (the Great Bear), which was thought to represent the catasterism of Callisto, who was transformed into a bear, and placed by Zeus among the stars. The myth explains why the constellation never sets below the horizon, saying that since Callisto had been Zeus's lover, she was forbidden by Tethys from "touching Ocean's deep", out of concern for her foster-child Hera, Zeus' jealous wife.
In Ovid's Metamorphoses, Tethys turns Aesacus into a diving bird.
Tethys was sometimes confused with another sea goddess, the sea-nymph Thetis, the wife of Peleus and mother of Achilles.
- Solid lines denote parent-child blood relationships
- Dashed lines denote marriage relationships that result in offspring
- † denotes the deceased
- Tethys was married to Oceanus.
- Tethys was said to have magnificent hair.
- Sometimes it was said she had a winged helmet.