Cronus overthrew his father Uranus to become ruler of the cosmos. However, both Uranus and Gaia prophesied that Cronus would be overthrown by one of his children. To prevent this, Cronus swallowed each of his children as they were born. Zeus was saved and grew up to defeat Cronus and the Titans with the aid of the Cyclopes and Hecatoncheires. Zeus then became the new ruler, exiling the Titans to Tartarus.