Gaia is the Earth Mother and Ouranos is the sky. They and two others were the first gods. The other gods were Tartauros, the Under Earth and Eros, the Sexual Urge.

Gaia and Ouranos were married and Eros urged Ouranos to impregnate Gaia. Gaia then gave birth to the Titans. The Titans were Oceanus, Hyperion, Promethesus, Epimethesus, Rhea, and Cronos. At birth all the Titans, except Cronos, who was raised in secrecy by his loving mother Gaia, were thrown away by Ouranos. When Cronos was older he cut his father into tiny little pieces amd made him give back the Titans.

Hence the phrase, "Young generation defeats old generation".