These are gigantic creatures. They were born from the union of Uranus (the Heaven) with Gaea (the Earth). They ruled the world before the gods. The most important ones are: Cronus, Rhea, Oceanus, Tethys, Mnemosyne. Also Elio, Prometheus and Atlas are considered as Titans. When Zeus deprived his father Cronus of his power, there was a battle. The Titans lost and they fell into the Hades behind bronze doors. These doors were guarded by the Giants. Although some Titans didn't take part in the war.