What is the fate of the former territory of Byzantium and its capital?

The Byzantine Empire had a leading position in the world for a long time, but it was subject to raids by nomadic tribes and a professional army from the east or west. She survived the Roman Empire for several centuries, but fell anyway. This happened in the 15th century. At this time, soldiers from Turkey attacked Byzantium once again. They plundered the empire and occupied the capital, Constantinople. There the Turks organized their own capital, Istanbul. After that, the Byzantine Empire fell, and in its place another – the Ottoman Empire – appeared.