The last emperor of the Byzantine Empire was Constantine XI Palaiologos. He reigned from 1449 until the fall of Constantinople to the Ottoman Turks in 1453. This event marked the end of over a thousand years of Byzantine rule and was the culmination of centuries of decline for the empire. Constantine XI is remembered for his bravery during the siege of the city, where he fought valiantly but ultimately perished during the battle. His legacy is one of resilience and determination against insurmountable odds.