In the beginning there was only Chaos. Then out of the void appeared Erebus, the unknowable place where death dwells, and Night. All else was empty, silent, endless, dark. Then, Love was born bringing along the beginning of order. From Love emerged Light, followed by Gaea, the earth.
Erebus slept with Night, eventually giving birth to Ether, the heavenly light, and to Day, the earthly light. Then, Night alone created Doom, Fate, Death, Sleep, Dreams, Nemesis, and all things that dwell in the darkness haunting mankind.
Meanwhile, Gaea alone gave birth to Uranus, the sky. Uranus became Gaea's husband, surrounding her on all sides. Together, they produced the three Cyclopes, the three Hecatoncheires, and twelve Titans.
However, Uranus was a cruel father and husband. He hated the Hecatoncheires and imprisoned them by pushing them into the hidden places of the earth, Gaea's womb. This angered Gaea and she plotted against Uranus. She made a flint sickle and tried to get her children to attack Uranus. All were too afraid, except the youngest Titan, Cronus.
Gaea and Cronus set up an ambush of Uranus as he lay with Gaea at night. Cronus grabbed his father and castrated him with the sickle, throwing the severed genitals into the ocean. It is unclear as to what happened to Uranus afterwards; he either died, withdrew from the earth, or exiled himself to Italy. As he departed, he promised that Cronus and the Titans would be punished. From the blood that was spilled on the earth due to his castration, emerged the Giants, the Ash Tree Nymphs, and the Erinnyes. From the sea foam that was produced when his genitals fell in the ocean, emerged Aphrodite.
Cronus became the next ruler. He imprisoned the Cyclopes and the Hecatoncheires in Tartarus. He married his sister Rhea, and had many children. He ruled for many ages; however, Gaea and Uranus both had prophesied that Cronus would be eventually overthrown by a son. To avoid this, Cronus swallowed all of his children as they were born. Rhea was angry at the treatment of the children and plotted against Cronus. When it was time to give birth to her sixth child, Rhea hid herself, then she left the child to be raised by nymphs. To conceal her act she wrapped a stone in swaddling cloths and passed it off as the baby to Cronus, who swallowed it.
This child was Zeus. He grew into a handsome youth at the island of Crete. He consulted Metis on how to defeat Cronus. She prepared a drink for Cronus designed to make him vomit the other children. Rhea convinced Cronus to accept his son and Zeus was allowed to return to Mount Olympus as Cronus's cupbearer, giving him the opportunity to serve Metis' potion to Cronus. The plan work perfectly and the other five children emerged out of Cronus. As gods, they were unharmed and thankful to their youngest brother, they made him their leader.
Cronus was yet to be defeated though. He and the Titans, except Prometheus, Epimetheus, and Oceanus, fought to retain their power; this led to the War between the Titans and the Olympians called Titanomachy. Atlas became their leader in battle and it looked for some time as though they would win and put the young gods down. However, Zeus was cunning; he went to Tartarus and freed the Cyclopes and the Hecatoncheires. Prometheus joined Zeus as well. He returned to battle with his new allies; the Cyclopes provided Zeus with lightning bolts for weapons; the Hecatoncheires were armed with boulders, waiting in an ambush. At the right time, Zeus retreated drawing the Titans into the Hecatoncheires's ambush, who rained down hundreds of boulders with such a fury that the Titans thought the mountains were falling on them. They ran away, leaving Zeus victorious.
However, even after this victory, Zeus was not safe. Gaea, angry that her children had been imprisoned, gave birth to her last child, Typhon. Typhon was the deadliest monster in Greek mythology and was known as the "Father of All Monsters". He was so fearsome that most of the gods fled; however, Zeus faced the monster and flinging his lighting bolts was able to kill it. Typhon was buried under Mount Etna in Sicily.
Much later, Zeus faced a final challenge set by the Giants. They went so far as to attempt to invade Mount Olympus, piling mountain upon mountain in an effort to reach the top. Nevertheless, the gods had already grown strong, and with the help of Heracles, the Giants were subdued and killed.
More: The Creation II
The Creation is also called Theogony.