Board Thread:Lore Discussion/@comment-24583421-20140302161145/@comment-13446185-20140717063832

Dragonlover553 wrote: No, he's dead. He never really was a god, just a guy with a lot of magic. He had an immortality spell(sort of) on him, and since it was powered by the magic of the Heart, when it was destroyed, the magic keeping him alive went with it. Sure, he was powerful, and immortal, and worshiped, but he wasn't a god.

Actually, Dagoth Ur was a god of sorts. The whole reason we had to fight his mortal self in TES: III was because his god form wouldn't except his death and kept on dreaming that he lived.