Rhea was a Greek Titan and mother of the Olympian gods. After her husband Cronus consumed their first five children, she saved her sixth baby, Zeus, by giving Cronus a stone to swallow instead.
The Titans were the first children of the primordial Greek deities Uranus and Gaia. Two of these Titans, Cronus and Rhea, became the parents of the original generation of Olympians, who overthrew the Titans, just as the Titans had overthrown Uranus before them.
Hestia was the firstborn child of the Titans Cronus and Rhea, rulers of the cosmos before the Olympians; her siblings included Demeter, Hera, Hades, Poseidon, and Zeus.