Board Thread:Lore Discussion/@comment-1600847-20160719191042/@comment-1600847-20160719204619

Zippertrain85 wrote: The Great War only doesn't say it's not part of the Empire, but doesn't actually say it is. Yes, it does... it lists High Rock, Hammerfell, Skyrim, Cyrodiil, and Morrowind as Imperial provinces...

" When  Titus Mede II  ascended the throne in  4E 168, he inherited a weakened empire. The glory days of the Septims were a distant memory. Valenwood and Elsweyr were gone, ceded to the Thalmor enemy.  Black Marsh  had been lost to Imperial rule since the aftermath of the Oblivion Crisis.  Morrowind  had never recovered fully from the eruption of  Mount   Vvardenfell  .  Hammerfell was plagued by infighting between  Crowns  and Forebears . Only  High Rock , Cyrodiil and  Skyrim  remained properous and peaceful. Emperor Titus Mede had only a few short years to consolidate his rule before his leadership was put to the ultimate test."

Morrowind is clearly listed in the paragraph discussing remaining Imperial provinces. You can argue that its left since the Great War, but it certainly was part of it during the Great War.