The Titans were: Kronos, Koios, Krios, Hyperion, Iapetos, Okeanos, Ouranos, and Gaia. They ruled the cosmos before the Olympians came to power. Hyperion, Koios, Krios, and Iapetos were all posted at the 4 corners of the world, and the Cyclopes and Hekatonkheires were placed in the pit of Tartaros.A prophecy was told that Kronos' children would overthrow him. Therefore, he ate all of his children as soon as they were born. When Zeus was born, Rhea gave to Kronos, the Titan-king, a rock to eat instead. When Zeus grew up he made Kronos disgorge his siblings, who, being immortal, were still alive. The gods then overthrew the Titans.
Pictures: http://www.fashion-res.com/EX/10-08-03/The%2520Battle%2520Between%2520the%2520Gods%2520a
nd%2520the%2520Titans.jpg
-http://www.theoi.com/Titan/
Titanes.html
