Pontus was the primordial Greek god who personified the sea and fathered a major family of marine beings. Unlike Poseidon, he was not chiefly a ruler of the sea or a god of earthquakes; he was the sea conceived as a primordial cosmic entity.
In Hesiod’s Theogony, written in the 8th or 7th century BC, Gaia—the Earth—produces Pontus without a father. Gaia and Pontus then become parents of Nereus, Thaumas, Phorcys, Ceto, and Eurybia. These descendants include benevolent sea powers, monstrous figures, and beings connected with the dangers of the ocean.
Pontus appears mainly in genealogies rather than adventure myths. That helps distinguish him from Poseidon, who plays an active role in stories involving heroes and cities. Thalassa is another personification of the sea, while Oceanus represents the world-encircling stream in older Greek cosmology. A later Latin tradition associates Pontus with Mare and makes him progenitor of fish.