They had twelve gods, Jupiter, Neptune, Pluto, Mercury, Mars, Vulcan, Apollo, Diana, Minerva, Juno, Ceres and Vesta. Besides these there were other lesser gods, Bacchus, Isis, Hebe, the Muses and the Fates, etc.; also Sleep, Dreams and Death; and there were still others who had free will and intelligence, and having mixed forms, such as the Pegasus, or winged horse, the Centaur, half man and half horse, Hydra, etc.
The Greek theory of the origin of things was that the beginning was chaos laden with the seed of all nature, then came the Earth and the Heavens, or Uranus; these two were married and from this union came a numerous and powerful brood. First were the six Titans, all males, and then the six females, and the Cyclops, three in number; these latter were of gigantic size, having but one eye, and that in the center of the forehead. They represented Thunder, Lightning and Fire, or the rapid flame.
The Titans made war upon their father and wounded him, and from the drops of blood which flowed from the wound and fell upon the earth sprang the Furies, whose names signified "Unceasing," "Envier," and "Blood-Avenger;" and the Giants and melian Nymphs, and from the blood drops which fell into the sea sprang Venus, the goddess of love and beauty.
The youngest and bravest son, Saturn, who wounded and dethroned his father, was, by the consent of his brethren, permitted to reign with an understanding that his male children should all be destroyed. But his wife, Rhea, hid from him three of her sons, Jupiter, Neptune and Pluto, who, waging a ten-year war against their father, finally dethroned him and divided the kingdom among themselves. The oldest, Jupiter, had the heavens, and reigned over all gods, Neptune over the sea, and Pluto the lower regions.
Jupiter then built his courts on Mount Olympos, reigned supreme god over heaven and earth; he was called the father of man and gods, and is placed at the head of the entire creation.
He is generally represented as majestic in appearance, seated on a throne with a sceptre in one hand and thunderbolts in the other. Jupiter had a number of wives; he also married his sister Juno, who was the queen goddess. Besides Jupiter, Juno, Neptune and Pluto the other eight gods were the children of Jupiter.
Neptune was second to Jupiter in power. He is represented as carrying a trident or three-tined fork, with which he strikes the earth and shakes it; he is therefore often called the "earth-shaker." He is usually represented like Jupiter, of a serene and majestic aspect, seated in a chariot made of shells and drawn by dolphins and sea-horses, while the Tritons and the Nymphs gambol about him.
Pluto is represented as the grim, stern ruler over hell. He is also called Hades and Orcus. He has a throne of sulphur, from beneath which flows the Rivers Lethe, or "Oblivion," Phlegethon, Cocytus and Acheron. In one hand he holds his fork and in the other the keys of hell, and beside him is the dog with three heads. He is described as being well qualified for his position, being inexorable and deaf to supplications, and an object of aversion and hatred to both gods and men. From his realms there is no return, and all mankind, sooner or later, are sure to be gathered into his kingdom.
As none of the goddesses would marry the stern and gloomy god, he seized Proserpine, the daughter of Ceres, while she was gathering flowers, and opened the earth and carried her through into his dominion.
Mercury was the messenger and ambassador of the gods. He was represented by wings on his hat, and sandals, and usually carrying a wand, or staff, with two serpents twined around it. He himself was a god of eloquence and the patron of orators, merchants, thieves, robbers, travelers and shepherds.