The Ottomans led by Sultan Mehmed II attacked and conquered the city of Constantinopole, protected by Constantine XI Palaiologos in 1453. This marked the end of the great Roman Empire and also is considered the end of the Middle Ages.
The Ottomans had several advantages over the defenders. They had vast resources at their disposal and built a large fleet of ships (estimated at 126) and had thousands of soldiers with them. The defenders were easily outnumbered by 1:10, both in terms of men and ships. The biggest advantage that Mehmed had was cannons, designed by Orban (by Mehmed himself as per some accounts). The largest cannon available to Mehmed was 27 feet long and could cast 600 lb stone balls over a distance of 1 mile. They also had a large number of medium sized cannons. These cannons provided superiority to the Ottomans as they continually bombarded the city's defensive walls during the seven-week long siege.