Poseidon is one of the 12 Olympian gods. Poseidon, the Lord of the Earth and the Sea A hymn to Poseidon included among the Homeric Hymns is a brief invocation, a seven-line introduction that addresses the god as both "mover of the earth and barren sea, god of the deep who is also lord of Helicon and wide Aegae[13], and specificies his twofold nature as an Olympian: "a tamer of horses and a saviour of ships." http://en.wikipedia.org/wiki/Poseidon