Board Thread:Lore Discussion/@comment-24241449-20131230200615/@comment-13446185-20140102202140

"Solitude, always one of the richest and most influential counties in Skyrim, has grown ever more powerful,"...

..."It has sought to expand its influence further by annexing several former Imperial fiefs, such as the island of Rosacrea, ruled directly by the Emperor since Uriel V conquered it in the 271st year. It has begun sponsoring exploratory missions even farther from the mainland into the misty waters of the Sea of Ghosts."

-Pocket Guide to the Empire, Third Edition: Skyrim

If the Empire can't even hold it's colonies in the Padomaic Ocean I doubt it could hold colonies on Akavir.