The Titan Gods ruled the ancients for quite a long time until the Olympian Gods organized a successful coup d'etat and took over the universe. Fortunately, everyone was immortal so no serious injuries were sustained.
Painting of the Titanomachy by Cornelis van Haarlem (1588)
Below is a post-modern trailer for the 1981 version of Clash of the Titans using contemporary audio and film editing techniques from the 2010 release, an interesting example of how the ancient stories evolve and are retold through the cycles of time.