The God Neptune
Originally a god of springs and streams, the Roman god Neptune became identified with the Greek god of the sea, Poseidon. Poseidon was a son of Cronus and Rhea, who were among the first deities. When the world was divided in three, Zeus received the earth and sky, Hades the underworld and Poseidon the sea. Neptune, thus, was associated with the sea, with horses, and also with fresh water all over. He was also associated with earthquakes and with certain mental ailments such as epilepsy. He was worshiped not only by those on the coasts, but also by everyone, even far inland, since he was the god of fresh water springs, streams, and even floods. In Rome, he was worshiped primarily as Neptune Equester, patron of horse-racing, and had several temples built near racetracks. His holiday, Neptunalia, was on July 23, on which tents or huts were made from foliage and the branches of bushes. Additionally, Poseidon was a major civic god of several cities, and appeared on many coins that we have as part of the historical record.
In art Poseidon's chariot was pulled by a hippocampus (a mythical sea monster, with a horse's front end and the rear end of a fish) or seahorses. He was associated with dolphins and three-pronged tridents. (In fact the trident often appeared alone, as his symbol.) He lived in a palace on the ocean floor, made of coral and gems. Poseidon was creative and liked to make up new monsters, such as the octopus and blowfish, to amuse the nymphs who lived in his waters. Since he was one of the senior-ranked gods, he was shown mature, with a beard. He was said to have a volatile, deadly temper, turning from pleasant to stormy in moments; sailors were wary of him and sometimes drowned horses as a sacrifice to his whims.
Neptune's wife was Amphitrite, but numerous myths about him describing relationships he consummated with various women (and men as well) - some are less than complementary to our present day sensibilities. Some of his more interesting conquests include Demeter, who changed into a horse to get away from him, but he in turn turned into a stallion and fathered a foal named Arion, who was capable of human speech. Another time, he shared relations with Medusa in a temple dedicated to Athena; as a result, Medusa was punished by being turned into the monster she is known as. Another time, he seduced a young man named Pelops, whom he later gifted with a winged chariot.
Poseidon butted heads with Athena when both competed to be the patron deity of Athens. They both made offerings to the citizens - Poseidon gave them a salty spring (or horses, depending on the source) while Athena gave them an olive tree, used for wood, oil, and food. Athena trumped Poseidon when the citizens chose her patronage, for her gift was more useful. On the other hand, Poseidon was also linked closely to Apollo; they were both associated with the Oracle at Delphi, and they often joined forces for various missions, such as being the patron deities of colonists. Spartan soldiers also sang hymns to Poseidon that were normally reserved for Apollo. And once, both deites offended Zeus and were sent to serve King Leomedon, who had them build walls around his city. When they weren't rewarded for their efforts, Poseidon sent a sea monster to attack the city - Heracles killed it.
