Compared to what I expect from others on this site, I am substantially underinformed on this topic. So, my question is, do the Byzantines not only beat back the Otts but take over large portions of what eventually was the Ottoman Empire? Or are they largely a state encompassing modern day Turkey and Greece? Or Just Thrace, Greece, Cyprus and a few other Mediteranean Islands? Hard to imagine they would retain boundaries as of 1204.
It seems to me that they lose out to the Atlantic trade much the same way the Ottomans did. The English, Portugese, Spanish, and French were going to head west or South regardless of who held Constantinople. They probably industrialize better than the Turks did. Given the shared religious background, the rivalry in the black sea and caucuses might have been more peaceful than what the Turks encountered with the Russians during the 18th and 19th centuries.
Interested to read more or learn why any of these statements are ASB.