Olympian, in Greek religion and mythology, one of the 12 important gods who succeeded the Titans as rulers of the universe. The divine family of the Olympians was headed by Zeus, who ruled the heavens and earth, and his queen, Hera. Zeus' brothers, Poseidon and Hades (also called Pluto), ruled the sea and underworld respectively. The divine children were Ares, Hermes, Apollo, Hephaestus, Athena, Aphrodite, and Artemis. It was said that Zeus' sister Hestia, who was also an Olympian, resigned her place to Dionysus. The Olympians, whose honors and attributes have come down to us almost entirely through Homer and Hesiod, lived in majestic splendor on Mt. Olympus. Similar to human beings in both physical appearance and character traits, the gods feasted on ambrosia and nectar and took special delight in their mortal loves. About the 6th cent. B.C. the Olympian gods began to yield in importance to the mystery cults (see mysteries).