Úranos

Hesiod's poem Theogonia ("On the Origin of the Gods" or also "The Birth of the Gods") describes the origin of Uranus as follows: "In truth at first Chaos came to be, but next wide-bosomed Earth, the ever-sure foundation of all the deathless ones who hold the peaks of snowy Olympus, and dim Tartarus in the depth of the wide-pathed Earth, and Eros, fairest among the deathless gods, who unnerves the limbs and overcomes the mind and wise counsels of all gods and all men within them. From Chaos came forth Erebus and black Night; but of Night were born Aether and Day, whom she conceived and bore from union in love with Erebus. And Earth first bore starry Heaven, equal to herself, to cover her on every side, and to be an ever-sure abiding-place for the blessed gods ..."

First, then, was Chaos. Then was born the Earth (Gaia) and in it the Underworld Abyss (Tartarus), and then Love (Eros). Next, out of Chaos is born Darkness (Erebos) and Night (Nyx). Then out of the Earth (Gaia) are born Heaven (Uranos) and the Sea (Pontos).

When Uranos ruled the world, he and Gaia begat twelve offspring (Titans). Subsequently, also the Cyclopes and the Hekatoncheires.

Úranos hated his descendants, so much so that he cast the Hekatoncheires into the bowels of the earth (Tartarus). Gaia then asked the Titans to remove Uranos from power. Only Kronos dared to do so, and he hacked Uranus to pieces with an iron sickle (other sources say he cut off his manhood). From Uranus' blood, Gaia gave birth to the Giants.
Another myth claims that Kronos threw Uranus's organs (in the other interpretation it was his manhood) into the sea, where they mixed with sea foam to create Aphrodite.