What exactly happened to Mehrune Dagon's realm? Obviously some Daedric civilization lived there once but they were destroyed. Did Dagon trash his own realm?

Dagon's realm is always an image of destruction.


That's not obvious.

As has been said by DarthRavanger, Mehruns Dagon's realm is an embodiment of destruction, being as he is the Prince of Destruction, so it's design is meant to invoke an image of destruction (and a generic video game vision of hell too, but since the people of Tamriel wouldn't know what the hell fictional writers envision in our world looks like, we'll focus on the destruction part here.) the whole fire and brimstone thing I suppose invokes ideas of destruction because it relates to things that can cause destruction, I don't see too much to suggest the existence of a dead civilization in the Deadlands, though, but if it is there, it's probably actually supposed to invoke the image of the destruction of civilization, how this would relate to Mehruns Dagon's sphere should be clear.

Buildings denote habitation. So someone built structures and then destroyed them in some nihilist gesture I assume?

Dagon thought it'd look just dandy to throw a building into a molten river of lava, and he might have also put daedra into it.

The only evidence of former inhabitants would be the burning corpses hanging everywhere, and impaled on pikes, and turned into flesh pods, but it's just as likely these are hapless inhabitants of Cyrodill pulled into the Gates by the Daedra.

I'm inclined to impart this lack of organized habitation (as opposed to monsters idly spending their lives in a tower waiting to be killed by the player character) to developer laziness (or lack of resources/time). If you want to see what an occupied Deadlands would look like, I'd suggest taking http://www.tesnexus.com/downloads/file.php?id=6779 for a try. It is a great mod, and I like how the author gave a structure and civilization (albeit an alien one) to the Dremora who inhabit Dagon's plane.

Given that Mehrunes Dagon is the Daedric Prince of Destruction and natural disasters, I'd wager that the structures are simply just getting destroyed and rebuilt over and over, given that the Deadlands are most likely not geologically stable.

This might even contribute to the caste system of the Dremora..the ones tough enough to survive the constant Destruction and who die the least possibly climb the ranks, while the poor hapless Darwin Award winners who keep getting killed get demoted to Churl status.

But why would the Dremora want to align with Dagon if Mehrunes treats them like crap?

1) He's a Daedric prince
2) Who says he mistreats them? They're kin to him, so it stands to reason that he'd treat them better than he would mortals.

I always figured the lack of habitation was because the worlds with the sigil keeps in were just staging posts for invasion. The fact that there was destroyed towers etc all over the place was just Dagon's decorating style. The realms are a reflection of ther Prince from whom they were created, so they come pre-destroyed...

I bet Anhaedra knows the answer.

It's the way he likes it

He must offer them something in return, or perhaps the Dremora feel Dagon gives them the best oppurtunity for combat? They do seem to possess a warrior culture.

Cliche ravaged the Deadlands.

Just like how it ravaged Cyrodiil, turning it into High Rock for the most part.

Heh. Cliche was a much deadlier invasion force than Dagon's armies ever were.

he finds a nice tower everyone likes, and he stomps it. he is the prince of destruction! He made his realm like that i guess.

Also, the whole design asthetic is the pit of a giant volcano! If ancient writings on Volcanoes are any inspiration, volcanoes are forces so powerful and deadly that they were thought (among other things) to be the wrath of the gods incarnate, able to swallow cities whole. Add to that that they didn't know when they would strike or which mountain might be one and you'd find volcanoes pretty frightening too.

Well, Mehrunes Dagon himself said it, so I guess that makes it cannon.

On the plus side, it at least makes more sense in the Daedlands since Dagon can make those however he wants, and his new decor still fits with his sphere even if it isn't the same as how they were described before. One can explain the Deadlands become a stereotypical fire and brimstone hell easily, but the same can't be said for Cyrodiil becoming a more boring version of Middle Earth.

Except Cyrodiil didn't become High Rock, it became Generic Fantasy Land, which High Rock happens to also be.

Well, since Boethiah & Peryite have a holiday resort in the Deadlands, it can't be all that bad.

I think it's closer to "the developers got lazy".

Although, I don't recall it ever being explicitly stated which realms any of Oblivion we visit, except for the Shivering Isles, are, although logic would lead one to assume that the realm from whence Dagon's invasion stems is his realm.

The Dremora are actually old Morrowind players with an IQ below 20 who console'd for Daedric armor in the census office, Mehrunes just found a use for them hah.