In Hesiod's Theogony, after Chaos appeared Gaea, or Ge, the mother of all creation. She gave a parthenogenetical birth to Uranus, the Sky, "whom she made her equal in grandeur so that he entirely covered her". Then, she created the high mountains and Pontus, "the sterile sea".
Gaea united with her son Uranus and gave birth to the first divine race-the Titans. There were twelve of them, six male: Oceanus, Coeus, Hyperion, Crius, Iapetus, Cronus; and six female: Theia, Rhea, Mnemosyne, Phoebe (1), Tethys and Themis (see genealogical table Uranus-Gaea). Uranus and Gaea then gave birth to the Cyclopes: Brontes, Steropes and Arges, who resembled the other gods but had only one eye in the middle of their forehead. Finally they gave birth to three monsters, Hecatoncheires: Cottus, Briareus and Gyges.
Uranus hated his offspring and as soon as they were born he shut them up in the depths of the Earth. Angry because her children were imprisoned, Gaea decided to take a revenge against her husband. She made a steel and fashioned a sharp sickle. Then she released Cronus, the youngest Titan, and encouraged him to castrate his father and rule in his place. When Uranus came to lie with Gaea that night, Cronus armed with a sickle, cut off his father's testicles and threw them into the sea. From the wound black blood dropped and the drops, seeping into the earth, fertilized Gaea and she gave birth to the Erinyes, the Giants, and to the ash-tree Nymphs, the Meliads. Uranus' discarded genitals broke into a white foam from which was born a young goddess, Aphrodite.
Another famous legend of Gaea is the one in which she helps her daughter Rhea when she was pregnant with Zeus, to protect the child from being eaten by Cronus (see Cronus, Zeus, Rhea).
After Uranus' castration, Gaea united with another of her children, Pontus, the sea, with whom she gave birth to five marine divinities: Nereus, Thaumas, Phorcys, Ceto, and Eurybia (see genealogical table Pontus-Gaea).
With Tartarus, Gaea gave birth to her youngest son Typhon, a monster of prodigious strength.
In other theogonies Gaea was said to have been the mother of Triptolemus by Oceanus. The giant Antaeus was also said to have been her son, by Poseidon. Other monsters considered by various mythographers as the children of Gaea include: Charybdis, the Harpies, and Python.
Gaea possessed a talent of foretelling the future. The Sanctuary at Delphi, the main centre of divination in ancient Greece, was originally sacred to Gaea, before it was won by Apollo. One of her famous oracles was the one in which she prophesied victory to Zeus in his struggle against the Titans if he liberated the Cyclopes and Hecatoncheires, whom Cronus had locked in Tartarus (see Zeus, Titans).
Gaea was at one time the supreme goddess, whose majesty was acknowledged not only by men but by the gods themselves. Later, when the victorious dynasty of the Olympians was established, her prestige was not lessened. It was still Gaea whom the gods invoked when they made oaths: "I swear by Gaea and the vast sky above her", Hera proclaims when, in the Homer's Iliad she answers Zeus' accusations.
Later, as other divinities rose in the estimation of men, the role of Gaea gradually became less important. Her cult, however, always continued in Greece. She was particularly venerated at Delphi and at Olympia. She had sanctuaries at Dodona, Tegea, Sparta and at Athens., She was offered first fruits and grain; but when she was invoked as the guardian of the sanctity of oaths a black ewe was sacrificed in her honour. She was commonly represented in the form of a gigantic woman.