Uranus was aghast by the sight of his offspring, the Cyclopes and the Hecatoncheires. (In a differing version Uranus was frightened of their great strength and the fact that they could easily depose him). He hid them away in Tartarus (the bowels of the earth) inside Gaia, causing her intense pain. The discomfort became so great that she asked her youngest son, Cronus, to castrate his father, as this would cease his fertility and put an end to more monstrous offspring. To accomplish this deed Gaia made an adamantine sickle, which she gave to Cronus. That night Uranus came to lay with Gaia. And as the sky god drew close, Cronus struck with the sickle and cut off Uranus's genitals. From the blood that fell from the open wound were born nymphs and giants, and when Cronus threw the severed genitals into the sea a white foam appeared. From this foam Aphrodite the goddess of love and desire was born.
A slightly differing version tells of Uranus being so vast that he could cover Mother Earth (Gaia) and easily take advantage of her fruitfulness, but Gaia tired of her exuberant fertility and begged her sons to free her from the excessive embrace of Uranus. All refused except Cronus. Armed with a sickle he castrated Uranus, and the blood which fell from the mutilation gave birth to the Erinyes (Furies), the Giants and the Meliae (Nymphs of the manna ash trees). And when Cronus threw the sickle into the sea the island of Corfu, home of the Phaeacians, sprang up).
After Uranus (the sky) had been emasculated, the sky separated from Gaia (the earth) and Cronus became king of the gods. Later, Zeus (the son of Cronus) deposed his father and became the supreme god of the Greek Pantheon.