Ottoman Sultan Mehmed II begins his siege of Constantinople. By this time the authority of the Byzantine Empire has shrunk to little more than the city of Constantinople itself. Mehmed II will breach the walls after only 50 days.
The Theodosian Walls protecting Constantinople had stood for more than a thousand years; when they fall, the Eastern Roman Empire (Byzantium) also ends.
After the Ottomans defeat the Byzantine Empire they will continued expanding into the Balkans and the Ottoman Turkish Empire will move its capital from Bursa to Istanbul (Constantinople). After 1500, the Moguls (1526-1857 CE) and the Safavids (1520-1736 CE) follow the military example set by the Ottomans and create two new empires.