Rhea was one of the Titans, the wife and sister of Kronos.
Rhea was the mother of Demeter, Hera, Hestia, Hades, Poseidon and Zeus. Zeus was the youngest, and the only one of her children who was not eaten by Kronos immediately after birth—Rhea instead handed Kronos a rock wrapped in clothing, which Kronos devoured believing it to be his infant son. Zeus, who was hidden away on the island of Crete later returned to free his siblings and overthrow Kronos and the Titans.
The Romans knew Rhea as Manga Mater (The Great Mother Goddess)