the-elder-scrolls-series
I see bits of text saying that the College of Winterhold was not affected by the disbanding of the Mages Guild.
But what is the story of the disbanding of the Mages Guild? What happened? Why was it disbanded? (For example, did they do something treasonous? And if so, what was it?)
This is a quick answer BUT in the Dragonsreach there is a book in the same room as the enchanting table that explains all events of Oblivion and briefly summarizes what happened in-between the games. Including that the Septim dynasty ended at the end of the main quest for oblivion and names the new dynasty that controls the empire.
Add On:
The third era ended and the fourth era begins when you and Martin Septim defeat/banish Mehrunes Dagon. Hit this site its a pretty good timeline for the 200 missing years including Hammerfells exit from the empire and Vvardenfell being destroyed.
My source is from Elder Scrolls Wikia and UESP.
*Depends on player's choice on Skyrim's Civil War.
Though, because of the White-gold concordat, the Aldmeri Dominion has HEAVY influence on the Empire, meaning they have a 5~6 province influence on Tamriel
Hammerfell is the only province that defeated the Aldemri Dominion, and Morrowind and Black Marsh are the only provinces that still haven't been attacked.
A curiosity, is that, while in Skyrim, the Thalmor are considered "bad guys," in Elsweyr, they are considered heroes by the Khajiit For restoring the two moons of Nirn, and I haven't checked what Bosmers think of them.
Best Answer
They were in-part blamed for the Oblivion Crisis, which caused havoc all over Cyrodiil. Of course they didnt have anything to do with it but the people had to blame somebody.