Final answer:
The Fall of Constantinople in 1453 marked the end of the Byzantine Empire and the beginning of Ottoman rule. Mehmed II converted the Hagia Sophia into a mosque, and the event had significant historical and cultural consequences.
Step-by-step explanation:
The Fall of Constantinople in 1453 was the event when the city of Constantinople, the capital of the Eastern Roman Empire (Byzantine Empire), was conquered by Muslim Turks. This conquest marked the end of the Byzantine Empire and the beginning of Ottoman rule. The conquering sultan, Mehmed II, recognized the beauty of the Hagia Sophia and saved it from destruction, converting it into a mosque. The fall of Constantinople had significant historical and cultural consequences, and it is still remembered as a major turning point in history.