Cronus married his sister Rhea, but it was prophesied that one of his own sons would dethrone him. Therefore he swallowed the children Rhea bore him: Hestia, Demeter, Hera, Hades, Poseidon. Rhea was enraged and bore Zeus in the dead of night so that she could give him to Mother Earth, who left him to be nursed by nymphs in a cave on Crete. Pan was his foster-brother and together they drank milk from the goat-nymph Amaltheia, whose image Zeus would later set amongst the stars as the constellation of Capricorn. One of her horns became the Cornucopia or horn of plenty.
Rhea had given her husband a stone in swaddling clothes to swallow, but Cronus found out and pursued Zeus. The baby's cradle was hung in a tree so that Cronus might find him neither in heaven nor on earth and was guarded by the Curetes, Rhea's sons. [presumably by another father! SK] Their shouting and banging of spears against shields drowned the noise of the wailing infant.
Zeus grew up with the sheperds of Ida and when he was older, asked to be made Cronus' cupbearer. He gave his father an emetic potion and out came the stone, together with his older siblings. He led them in a ten-year war against the Titans, who, after this fiasco, had replaced Cronus as their leader by Atlas.
Zeus released the Cyclopes and the Hundred-handed Ores from Tartarus and in return they gave him the thunderbolt, Hades a helmet of darkness and Poseidon a trident, which they used to defeat Cronus: Hades stole Cronus' weapons without being seen, Poseidon distracted him with his trident and Zeus struck him down. All the male Titans were banished to a British island, far west, or Tartarus [one might wonder how much of a difference there is between these sentences... SK], except Atlas, who was made an example of, being ordered to carry the sky on his shoulders [not the earth!]. The Titanesses were spared.
Zeus set up the stone Cronus spat out at Delphis. Some say Rhea gave Cronus a foal to eat instead of Poseidon.
Robert Graves, The Greek Myths. Complete Edition.