From the Game's Introduction:
Tyrathia, a newly formed world, has begun to spawn life in its most simple forms. But before even the first sparks of life ignite, three Gods from a distant plane arrive, with the thought of claiming the world as their own. Each escaping their home for different reasons, they attempt to share the planet and to live in separate regions. For many years, the three Gods are content as they help to shape the world around them. But one by one, they all began to believe that they should rule over the others. What started as talks quickly became battles and so began the war.
For thousands of years, the new races fought in the name of their creators until most of those suited for war had fallen. All of the races and the gods saw extinction on the horizon and called for a truce.
A few millennia have pasted since the end of the second war. The descendants of the gods are very different now. Instead of being comprised of a single God, they have all started to assimilate into one another. They now share traits of all three Gods. They no longer wish to conquer the world for a single God, instead they wish to conquer it for themselves. Thus began the Third War. The creatures of the world now battle each other in petty battles over land, resources or dominance.