For this failing, Gaia foretold that Cronus would eventually be overthrown by one of his children, as he had overthrown his own father. To prevent this, as each of his children were born, Cronus swallowed them whole; as gods they were not killed, but imprisoned within his belly. His wife, Rhea, sought her mother's advice to avoid losing all of her children in this way, and Gaia advised her to give Cronus a stone wrapped in swaddling clothes. In this way, Zeus was spared the fate of his elder siblings, and was hidden away by his mother. When he was grown, Zeus forced his father to vomit up his siblings, who rebelled against the Titans. Zeus released the Cyclopes and Hecatoncheires, who became his allies. While the Hundred-Handed Giants fought alongside Zeus and his siblings, the Cyclopes gave Zeus his great weapon, the thunderbolt, with the aid of which he was eventually able to overthrow the Titans, establishing himself as the ruler of the cosmos.