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So, recently I have been quite obsessed with the Byzantine Empire. I have been thinking quite a lot about what were their chances to survive the Turks and turn the tide. Obviously by 1401 it's too late, but was there a real chance in the last 50-100 years prior to that?

Maybe the Nicopolis crusade succeeds, and something leads to the decline of Venetian and Genoan influence in the region. Any thoughts, or had the population of the area simply gone too far to be revived and a POD far earlier would be needed? Or are there any timelines on this site about something similar to this?
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