Castration and overthrow
As Hesiod tells the story, Gaia "first bore starry Heaven [Uranus], equal to herself, to cover her on every side, and to be an ever-sure abiding-place for the blessed gods." Then, with Gaia, Uranus produced eighteen children: the twelve Titans, the three Cyclopes, and the three Hecatoncheires (Hundred-Handers), but hating them, he hid them away somewhere inside Gaia. Angry and in distress, Gaia fashioned a sickle made of adamant and urged her children to punish their father. Only her son Cronus, the youngest Titan, was willing to do so. So Gaia hid Cronus in "ambush", giving him the adamantine sickle, and when Uranus came to lie with Gaia, Cronus reached out and castrated his father, casting the severed testicles into the sea. Uranus's castration allowed the Titans to rule and Cronus to assume supreme command of the cosmos.
For this "fearful deed", Uranus called his sons "Titans (Strainers) in reproach" and said that "vengeance for it would come afterwards." According to Hesiod, from the blood that spilled from Uranus onto the Earth came forth the Giants, the Erinyes (the avenging Furies), and the Meliae (the ash-tree nymphs). From the genitals in the sea came forth Aphrodite. According to some accounts, the mythical Phaeacians, visited by Odysseus in the Odyssey, were also said to have sprung from the blood of Uranus's castration.
Various sites have been associated with Cronus's sickle, and Uranus's castration. Two of these were on the island of Sicily. According to the Alexandrian poet Callimachus (c. 270 BC), Cronus's sickle was buried at Zancle in Sicily, saying that it was "hidden in a hollow under the ground" there. The other Sicilian site is Drepanum (modern Trapani), whose name is derived from the Greek word for "sickle". Another Alexandrian poet, Lycophron (c. 270 BC), mentions "rounding the Cronos' Sickle's leap", an apparent reference to the "leap" of the sickle being thrown into the sea at Drepanum.
However, other sites were also associated with the sickle. The geographer Pausanias, reports that the sickle was said to have been thrown into the sea from the cape near Bolina, not far from Argyra on the coast of Achaea, and says that "For this reason they call the cape Drepanum". The historian Timaeus located the sickle at Corcyra, which the islanders claimed to be Phaeacia, the island home of the Phaeacians, who (as noted above) were said to have been born from the blood of Uranus's castration.
After his castration, Uranus recedes into the background. Uranus plays no further role in Greek mythology beyond the tradition that he and Gaia (now reconciled?) warned their son Cronus that he was destined to be overthrown by one of his children, advised their daughter Rhea, Cronus's wife, to go to Lyctus on Crete to give birth to Zeus, so that Zeus would be saved from Cronus, and advised Zeus to swallow his first wife Metis, so that Zeus would not in turn be overthrown by his son. He is, however, identified on the Gigantomachy frieze on the Pergamon Altar, bearded and winged, fighting against the Giants with a sword, not too far from his daughter Themis, who is seen attacking another Giant.
