Poseidon is one of the twelve Olympian deities of the pantheon in Greek mythology. His main domain is the ocean, and he is called the "God of the Sea". Additionally, he is referred to as "Earth-Shaker" due to his role in causing earthquakes, and has been called the "tamer of horses".
The name of the sea-god Nethuns in Etruscan was adopted in Latin for Neptune in Roman mythology; both were sea gods analogous to Poseidon. Linear B tablets show that Poseidon was venerated at Pylos and Thebes in pre-Olympian Bronze Age Greece as a chief deity, but he was integrated into the Olympian gods as the brother of Zeus and Hades. According to some folklore, he was saved by his mother Rhea, who concealed him among a flock of lambs and pretended to have given birth to a colt, which was devoured by Cronos.
There is a Homeric hymn to Poseidon, who was the protector of many Hellenic cities, although he lost the contest for Athens to Athena. According to the references from Plato in his dialogue Timaeus and Critias, the island of Atlantis was the chosen domain of Poseidon.
Poseidon was a son of Cronus and Rhea. In most accounts he is swallowed by Cronus at birth but later saved, with his other brothers and sisters, by Zeus. However in some versions of the story, he, like his brother Zeus, did not share the fate of his other brother and sisters who were eaten by Cronus. He was saved by his mother Rhea, who concealed him among a flock of lambs and pretended to have given birth to a colt, which she gave to Cronus to devour.
According to John Tzetzes the kourotrophos, or nurse of Poseidon was Arne, who denied knowing where he was, when Cronus came searching; according to Diodorus Siculus Poseidon was raised by the Telchines on Rhodes, just as Zeus was raised by the Korybantes on Crete.
According to a single reference in the Iliad, when the world was divided by lot in three, Zeus received the sky, Hades the underworld and Poseidon the sea. In the Odyssey (v.398), Poseidon has a home in Aegae.