The Ottomans, led by Sultan Mehmed II, lay siege to the city of Constantinople. In the defense of his capital, the Byzantine Emperor, Constantine XI counts on his citizens and reinforcements from Genoa and Venice. However, on May 28, 1453, the final Ottoman assaults overtake the city. The Byzantine Empire, last remnant of the Roman Empire and guardian of the orthodox faith in the East, has just collapsed. Part of the "Butterfly Effect" series.