Before Zeus ruled Olympus, twelve Titans held the cosmos, and lost it
The Titans were the old guard of Greek myth: twelve children of Sky and Earth who ruled until Zeus toppled them in a ten-year war. Oddly, most of them barely have personalities. Many seem to exist mainly to parent more famous gods, and they may have been imported from Near Eastern stories.
Hesiod's Theogony gives the standard family tree. Uranus (Sky) and Gaia (Earth) produced six male Titans, including Oceanus, Hyperion and Cronus, and six female ones, among them Rhea, Themis and Mnemosyne. Uranus hated his offspring, which also included three Cyclopes and three Hundred-Handers, and hid them inside Gaia. She forged an adamant sickle, and only Cronus, the youngest Titan, dared use it, castrating his father and taking command.
Cronus then feared the same fate. Warned that a child would overthrow him, he swallowed each baby Rhea bore: Hestia, Demeter, Hera, Hades and Poseidon. When Zeus was due, Rhea went to Crete, and Cronus gulped down a stone wrapped in infant clothing instead. Grown up, Zeus forced his siblings back out, and the new gods fought the old in the Titanomachy, a decade-long war. The losers were locked in Tartarus, though a few, such as Oceanus and Helios, stayed free.
As characters, the Titans are thin. Apart from Cronus, Homer names only Iapetus as one of them. Several appear to serve a purely genealogical role: Coeus and Phoebe matter because their daughter Leto bore Apollo and Artemis, and Iapetus because he fathered Atlas and Prometheus. Hesiod may even have invented some names simply to reach twelve, perhaps to mirror the twelve Olympians. The group had no role in Greek cult worship.
The lineup was never fixed. Homer hints at a tradition in which Oceanus and Tethys, not Sky and Earth, were the first parents, and Plato's genealogy appears to try to reconcile the two. Apollodorus adds Dione as a thirteenth Titan. An older theory held that the Titans were gods of an earlier Greek people displaced by invaders; that idea has been abandoned. Their myth seems instead to have been borrowed from the Near East to give the Olympians a backstory of conquest.
Source: Titans
