The Castration of Uranus by Saturn

Uranus fathered the Titans upon Mother Earth, after he had thrown his rebellious sons, the Cyclopes, into Tartarus, a gloomy place in the Underworld, which lies as far distant from the earth as the earth does from the sky; it would take a falling anvil nine days to reach its bottom. In revenge, Mother Earth persuaded the Titans to attack their father; and they so, led by Cronus (Saturn), the youngest of the seven, whom she armed with a flint sickle. They surprised Uranus as he slept, and it was with the flint sickle that the merciless Cronus castrated him, grasping his genitals with the left hand (which has ever since been the hand of ill-omen) and afterwards throwing them, and the sickle too, into the sea by Cape Drepanum. But drops of blood flowing from the wound fell upon Mother Earth, and she bore the Three Erinnyes, furies who avenge crimes of parricide and perjury – by name Alecto, Tisiphone, and Megaera. The nymphs of the ash-tree, called Meliae, also sprang from that blood.
– The Castration of Uranus, quote by Robert Graves, The Greek Myths: 6.a.1