|From Hesiod's Theogony (loosely
In the beginning there was only Chaos, an empty void. This huge vacancy gave birth to Gaea (the earth), to Tartarus (the great region beneath the earth), to Eros (the god of love and attraction, to Erebus (the darkness of the underworld), and Night (the darkness over the earth). Then Erebus slept with Night, who gave birth to Aither (the heavenly light), and to Hemera (the earthly light). Later Night alone produced Doom, Fate, Death, Sleep, Dreams, Nemesis, etc. Meanwhile Gaea alone produced Uranus (the starry sky), the Mountains, and Pontus (the sterile sea). Uranus became mate and equal to Gaea, because he "covered" her on all sides. As a couple (he-sky, her-earth) they procreated the Twelve Titans, the three Cyclopes, and the three Hecatoncheires (with the fifty heads and hundred arms each). Uranus hated these latter children, and they hated him. In anger he pushed them back into Gaea's womb and kept them there. This was very painful for Gaea and she plotted revenge against Uranus. She fashioned a flint sickle and called upon her children to avenge her. All but Cronus, the youngest Titan, refused to help her for fear of Uranus's wrath. That night, when Uranus came to lie with Gaea, Cronus, hiding in ambush, was able to grab his father's genitals and sever them with the flint sickle. As the blood fell to the earth the Furies, the Ash-Tree Nymphs, and the Giants were created. When Cronus heaved the testicles into the sea Aphrodite arose from the foam. We hear no more of Uranus in the myths. Cronus then became leader of the Titans, and confined the Cyclopes and the Hecatoncheires to Tartarus. He married his sister Rhea and they produced many offspring. But Cronus had been warned by both Uranus and Gaea that a child of his would replace him as leader of the Titans, so when Rhea gave birth to a child and presented it to Cronus he would swallow the baby. This is what happened to Hestia, Demeter, Hera, Hades, and Poseidon shortly after each was born. Rhea finally wised up, and when Zeus was born she presented Cronus a stone wrapped in the swaddling clothes, which he swallowed thinking it was the newest child. Zeus grew to manhood on the island of Crete, attended to by nymphs. He sought and got advice from Metis, another Titaness, who prepared an emetic potion for him. Soon, disguised as a cupbearer, he was able to get Cronus to drink the potion. Cronus immediately vomited up all the children he had swallowed, all safe and sound, and fully grown. They overwhelmed Cronus and bound him as a prisoner in Tartarus. And so the Olympians began their rule. (It took ten more years of strife and wars between Titans, Olympians, Cyclopes, Hecatoncheires, assorted monsters and dragons (like Typhoeus) before the rule of the Olympians was solidified.)
Another Creation Myth
This story is a much earlier version than that above.
Eurynome, the goddess of all creation, arose from Chaos and separated the sea from the sky. Then, dancing naked upon the waves, she created the wind and rubbed it in her hands to create the serpent Ophion, who made love to her. Pregnant, Eurynome laid the World Egg, and Ophion coiled around it and hatched it. This egg brought forth the cosmos and everything in it. Eurynome and Ophion settled on Mount Olympus, and here, soon, Ophion was proclaiming himself creator. Eurynome, angry, banished him to the netherworld. Then she established the seven planets, each with a Titan and Titaness to rule it. When man appeared, he sprang from the soil, and the first man, Pelasgus, taught the others to eat acorns, build huts, and make clothes.