Hello, I am currently studying both the Byzantine Empire and the Ottoman Empire. I am having problems pegging a precise "point of no return" for Byzantium, that is, the point at which saving, and even restoring the empire would have been possible. It is silly to think that by the 15th century the only reason it didn't recover was because of poor leaders. Manuel and Konstantinos weren't even that poor actually. But anyway, my question in this: What would you say was the last point of redemption for the last survivor of Antiquity? I appreciate your insightful responses.