So, I currently realized that the Oghma Infinium's http://www.uesp.net/wiki/File:SR-book-Oghma_Infinium_1.png looks just like the Imperial City from above. So I have some weird theory/idea I'd like to discuss. We know that the Mysterium Xarxes is originally from the Oghma, and that it was given to Mehrunes by Xarxes, from Hermaeus Mora, the "All Knower" Mehrunes obviously didn't like something or everything about the 'mortal world' thus he attacked. But could the other daedra be involved too? We never hear about the other Daedra doing anything in the Oblivion Crisis. Well I find it interesting that Hermaeus Mora basically handed Mehrunes a map to a city that he was going to attack hundreds of years later. Also, if you read The Infernal City, Clavicus Vile's City Umbriel basically carved a dread path through Black Marsh. It's not confirmed weather Clavy willed this to happen, I'd vote on a sort of "reverse psychology" that he's known for. Such as "oh don't take my powerful city across Black Marsh, it'll kill everyone" Him knowing that Vuhon would, tempting him.

Also, Boethiah is known for deceit secret plots of murder and such. Maybe Mehrunes had Boethiah Govern over the Emperor's Death to start a chain reaction, leaving the Empire weak.

The Crimson Plague could have been set on by Peryite, in an effort to cause chaos to set an un-balance between nations.

What I'm trying to get at is, could the daedra have had a long term (over many eras) plan to kill off mortals? Even if it was slight action to cause a dispute between races to force them not to join sides many years from the present game, or cause an alliance that would strengthen one side, while weakening the others?

another example I have is say some daedric prince like "whispered" in the Aldmeri Dominion's ears causing them to take over the Empire, after it was weakened from Mehrunes attack, which would cause the Nords of skyrim to revolt, which they already have. Leaving the Daedra an open field where they won't have to worry about the Nords defending the Empire.

This is all just a theory, it could easily be proven wrong. I'd just like some "lore expert" insight.

EDIT: English is not my first language, so I'm sorry for any grammar or spelling mistakes.