Board Thread:Lore Discussion/@comment-39143771-20190415065121/@comment-76.198.193.113-20190620054646

Dragons went basically extinct in the1st Era after the fall of the Dragon Cult in 1E 140, and would not be seen in Skyrim till the 4th Era with the return of Alduin in 4E 201 or when TES:V is placed. Also Mephala wasn't an actor in the Oblivion Crisis, only Mehrunes Dagon and the daedra from his plane. It was his cult, the Mythic Dawn, that started it by killing the emperor and opening the gates. Also the Dragonborn had been around much earlier and the first, Mirrak from the Skyrim DLC Dragonborn, was a Dragon Priest before betraying them (though it was with a daedric prince which maybe lines with your theory) After Tiber Septim became emperor the dragonborn was whoever was emperor. The Oblivion Crisis was actually ended by a Dragonborn, Martin Septim, when he became an avatar for Akatosh and defeated Dagon. Also Mephala rarely has anything to gain from her schemes, they're purely entertainment.

Skyrim, as far as we know,probably did not fare well in the crisis. The Old Holds; the Rift, the Pale. Eastmarch, and Winterhold, were at least attacked.

The rest is from memory and my own theories

Skyrim fared well because they didn't rely on the empire and didn't have daedra worshipers. In Cyrodil their forces were spread across an empire, morrowind was in a civil war, and the Summerset Isles have an altmer infestation and those darned elves love joining up with Daedric Princes. Skyrim has been the evangelical equivilent for the nine (e.g. the stormcloaks) and each hold has a malitia.

Only the Old Holds were attacked because they're bordering Morrowind and daedric worshipers from there could set up gates easier. The Old Holds probably fared well. Winterhold had the College and was still a powerful city since The Great Collapse hadn't happened yet, Eastmarch is perpetually militarized and any siege on Windhelm would be forced to attack the bridge to get into the city, Riften had been built into a stronghold in preperation for an Akaviri invasion in the 2nd Era, and Dawnstar was more of a stronghold than we see it in skyrim.

Also the Daedra and the Mythic Dawn were pretty crap to be honest. They were extremely unorganized and had no military organization so when they would have faced Skyrim's experienced and prepared militias they would've lost. It's the same reason Blackmarsh beat them so badly because they were so well organized. Also to join the cult you had to read a bunch of books, which were very expenive, and find codes in them. Sadly for Dagon it's hard to take over the world when you're entire fan club is only rich literary nerds.