Chronus was the youngest son of the primordial deities Uranus (the god of the sky) and Gaea (the goddess of the earth). He overthrew his father and became the ruler of the Titans. Chronus married his sister Rhea, and they had six children: Hestia, Demeter, Hera, Poseidon, Hades, and Zeus.
Chronus feared that one of his children would overthrow him, just as he had overthrown his own father. So he swallowed each of his children as soon as they were born. Rhea was horrified by this, and she managed to save Zeus by tricking Chronus into swallowing a stone instead.
Zeus grew up in secret, and when he was old enough, he challenged Chronus to a battle. Zeus was victorious, and he freed his siblings from Chronus's stomach. The Olympians, as the children of Zeus and Rhea were known, then defeated the Titans and became the new rulers of the universe.
Chronus and Rhea were worshipped by the ancient Greeks as deities of time and fertility. They were often depicted in art as a pair, with Chronus holding a scythe or an hourglass, and Rhea holding a cornucopia or a baby.
