The Titans were a race of gods who were the parents and precursors of the Olympians. They were defeated by this younger generation of deities, who were led by Zeus. The ancient Greek poet Hesiod, in his Theogony, claims that the goddess Gaia first gave birth to Ouranos, then mated with him to produce these offspring. Later, Ouranos was to name his children Titans, which translates into overreachers.
Note that the names in parentheses are Roman versions.
Atlas | Atlas led the struggle between the Titans and Olympians, and for this he was punished.
Epimetheus | This Titan was the brother of Prometheus. His name means “afterthought”.
Gaia (Tellus) | Gaia was an Earth goddess. She is also the mother of the Titans.
Hyperion | God who was the father of Helios, Eos, and Selene.
Iapetos | God who fathered Atlas, Prometheus, and Epimetheus.
Koios | God who mated with Phoebe, and together they produced Leto and Asteria.
Kreios | God who sired Astraios, Pallas, and Perses.
Kronos (Cronus) | It was Kronos, son of Gaia and Ouranos, who castrated his father. Kronos was the sire of many of the Olympians.
Leto (Latona) | The goddess Leto bore the Olympian deities Artemis and Apollo to Zeus.
More Titans (Mnemosyne - Themis)