The very first of the Greek gods, the father to them all, Uranos was a sky-god, a son of Gaea, whom he later married, fathering the races of the Titans, the Hekatoncheires and the Cyclops. The Titans, twelve in number, rose against Uranos, and were defeated by him, being cast into Tartaros for their crimes. ButGaea, grieving for her sons, presented Kronos with a knife, and showed him how towound their father fatally. This was done, the Titans were set free, and Kronossupplanted his father. Thereafter was the race of Greek gods brought intoexistence.