Cronus sired six children by Rhea: Hestia, Hades, Demeter, Poseidon, Hera, and Zeus in that order, but swallowed them all as soon as they were born except Zeus, since Cronus had learned from Gaia and Uranus that he was destined to be overcome by his own child as he had overthrown his own father. When Zeus was about to be born, however, Rhea sought Uranus and Gaia to devise a plan to save him, so that Cronus would get his retribution for his acts against Uranus and his own children. Rhea gave birth to Zeus in Crete, handing Cronus a stone wrapped in swaddling clothes, which he promptly swallowed.
Then she hid Zeus in a cave on Mount Ida in Crete. He was suckled by his first cousin, a goat named Amalthea, while a company of Kouretes, soldiers, or smaller gods, shouted and clashed their swords together to make noise so that Cronus would not hear the baby's cry.
Zeus forced Cronus to disgorge the other children in the reverse order in which they had been swallowed, the oldest becoming the last, and youngest: first the stone, which was set down at Pytho under the glens of Parnassus to be a sign to mortal men, then the rest. In some versions, Metis gave Cronus an emetic to force him to disgorge the babies, or Zeus cut Cronus' stomach open. Then Zeus released the brothers of Cronus, the Gigantes, the Hecatonkheires, and the Cyclopes, who gave him thunder and lightning, which had previously been hidden by Gaia. Zeus and his siblings, together with the Gigantes, Hecatonkheires, and Cyclopes, overthrew Cronus and the other Titans. Similarly, in later myths, Zeus would swallow Metis when she was pregnant with Athena, because of a prophecy that said she would later give birth to one who would be more glorious than the father. Athena was born unharmed, bursting out of his head in full armor.