Board Thread:Warhammer 40k General Discussion/@comment-9558536-20130517084538/@comment-3258762-20130520113706

The Emperor is more powerful than the Chaos Gods. He is older than all of them combined...okay, maybe not that old but still, he was born around 60 000 BC while Nurgle was born around 900 AD

And, during the Age of Apostasy, the reason there were so many warp storms was because the 4 Chaos Gods tried to make a push against the Materium, during which only the Emperor stood against them in the Warp, and he beat them back.