This is the closest thing I can find; This History of Tamriel: Every Decade is a video which maps out the events that happened throughout the history of Tamriel, including geopolitical boundaries. I would suggest if you need a GIF use one of the many YouTube video downloaders then use a second tool to convert the video to a GIF - search for both, you'll find plenty of tools for them.
I for one am quite interested in the very comprehensive lore that sits in the background of each Elder Scrolls title and have spent many an hour perusing the History of Tamriel. Although not an image you'll find everything that ever happened - not only on Tamriel but on the Daedric planes too - including every shift in political alignment.
From the link above you'll find detailed histories of the three largest dynasties of the empire; Reman, Septim and Mede. There's also histories of provincial and ancient dynasties such as the Ayleids.