Board Thread:General Discussion/@comment-8435644-20130627180223/@comment-5989209-20140810142810

Miraak was not immortal. He was using the power of a Daedric Prince, and even if he wasn't, Time does not flow the same in Oblivion as it does on Nirn. That's why Jagar Tharn put Uriel Septim there. He could rule for centuries before the Dragonfires would go out.