Walls of Constantinople
Larger cannon were used in greater numbers during the Fall of Constantinople: Sultan Mehmet II used 68 Hungarian-made cannons, the largest of which was 26 feet long and weighed 20 tons; this fired a 1,200 pound stone cannonball, and required an operating crew of 200 men, as well as 70 oxen and 10,000 men just to transport them. For the defenders, the Walls of Constantinople could not be adapted for the operation of artillery, and towers were not good gun emplacements. There was even worry that the largest Byzantine cannon could cause more damage to their own walls than the Turkish cannon. The changing needs of cannon operation thus led to the development of "trace italienne" of Italy and the Tudors' Device Forts in England, using specially built cannon batteries to their greatest effect.