AP World History

Answer - A - Constantinople was captured by the Ottoman Empire under Sultan Mehmed II in 1453.

Key Takeaway: In 1453, Constantinople, which was the capital of the powerful Byzantine Empire at the time, fell to the Ottoman Empire, under Sultan Mehmed II. The siege of the city lasted nearly two months as Emperor Constantine XI attempted to maintain his hold on the city. The Fall of Constantinople marks the official end of the independence of the Byzantine Empire, which at that point was roughly 1,000 years old.