I have done alot of studying on the Romans including the eastern empire and one thing stuck out for me like a sore thumb: Why no succession laws? Unless the current living emperor appointed a co emperor it was the wild wild west as to who would succeed them which caused civil wars constantly. Why didnt they solve this by passing clear succession laws? From my point of view the empire was destroyed from the inside by civil wars by disputes who was supposed to be emperor. Alexios IV caused the fall of Constantinople by the crusaders, directly leading from his father deposed by Alexios III. Things seemed to calm down in the last couple hundred years but as you know there were periods where an emperor wouldn't rule for a week before he was deposed.

I firmly believe we would still have them around in some form if there were clear laws saying who had the right to rule instead of a free for all.