Social Impact of Cannons

Cannons revolutionized the way people fought and defended. Once impenetrable castle walls and citadels that took months, even years to conquer were now easier to capture. Towns were now more vulnerable to successful sieges and raids. Cannons forced castle architects to go back to the drawing board, both literally and figuratively, and redesign castle walls because the walls were tall, flat and easy targets for the cannons. Many responded by thickening castle walls with piles of dirt called ramparts. Most of the time, ramparts were proven to be ineffective because they weakened the building material rather than strengthening it. Others dug deeper and wider moats or had rounded walls built. Rounded walls were created to try to make a “glancing shot” rather than a direct hit that a flat wall would end up taking, and were effective designs. The negative of rounded walls was that they were often too expensive for villages/towns/cities to build.
Leon Battista Alberti, an Italian author, artist and architect, among other things, wrote the De re aedificatoria, which were five requirements that castles would need to meet in order to successfully defend against cannon attacks. These were:

1) Fortification walls facing gunpowder weapons should be both short enough to easily see the ground below them, and wide enough to withstand the impact of cannonballs.

2) Artillery towers projecting at an angle beyond the walls should be added to the fortification- this would not only protect the fortification itself but also keep offensive guns at bay and cover blind spots along the fortress walls,

3) Angled bastions projecting out at regular intervals from the fortress wall should be built, giving increasing flanking cross-fire along the surface of those walls,

4) As time passed, further refinements should be added to the fortification: wide and deep ditches along the walls to keep enemy artillery at a distance and to cut down on mining with detached bastions built beyond those ditches to further impede enemy artillery attacks, and

5) Extensions should be built to these fortifications, complete with crownworks or hornworks, to protect these outside strategic areas.