In the early days of Creation, a being of Chaos somehow entered the Prime Material Plane and raped an Aldar named Maya. Maya gave birth to two strange creatures: the first humans. The twins' names were Sinope and Callisto. Proteus ordered the Aldar to build a land for them named Ceylon, Land of the Dawn, on the continent we now know as Sapience. He also decreed that the Aldar should not try to exercise dominion over them.
A faction of the Aldar became resentful of the treatment over this new race of humans. This resentment factored greatly in the ability of the three gods of the Triumvirate to begin a war to overthrow Proteus from his position as leader of the Gods. Hence, this war is known as the War of Humanity and is directly linked to the Chaos Wars that soon followed.