Board Thread:Lore Discussion/@comment-10993011-20130618024431/@comment-12599067-20130803152059

Alduin... he is the World Eater, firstborn son of Akatosh and destroyer of worlds.He is the most ancient and powerful of all the dov, so powerful that time itself could not defeat him. Instead, one mortal, blessed by the same god Akatosh, was destined to defeat him, with the help of the old and wise Paarthurnax.

Retrospectively, Akatosh just turned his back on Alduin.