In which year did the Ottoman Empire conquer Constantinople? The answer is 1453.
The conquest came after a 53-day siege led by the 21-year-old Ottoman sultan Mehmed II, later known as Mehmed the Conqueror. Ottoman forces captured the city on 29 May 1453, ending the Byzantine Empire and making Constantinople the Ottoman capital.
The city’s famous Theodosian Walls had protected it for centuries, but Mehmed’s army used large gunpowder cannons and sustained assaults to breach the defenses. The Byzantine defenders were commanded by Emperor Constantine XI Palaiologos, who died during the final fighting.
A common mix-up is confusing the conquest with the Fourth Crusade’s capture of Constantinople in 1204. That earlier event was carried out by Western Christian crusaders, whereas 1453 marks the Ottoman conquest and the definitive end of the Byzantine state. The city remained central to Ottoman power until the empire’s final years.