Byzantine Empire existed from 395 to 1411 and was ruled by emperors from 16 dynasties. It doverged mainly in 1306. Henry VII of Luxembourg was affraid that Bohemia-Poland War might effect him and tried to give his wifes to daughters and give his daughter Marie to Andronikos III Palaiologos. Only son Andronikos IV Palaiologos then tried to get rid of Osmans and started major height within Osmas. As his grandson Andronikos V tried to extand it, Osmans started war against them and in 1409 entire empire crushed. Last resored in what we in our timeline call Istanbul Province osmans won against Andonikos in 1411 and entire empire felled under osmans. Andronikos V ended as Count of Luxembourg, title Andronikos IV was given as first in line after death of John the Blind .