Defense Against the Cannon

Guns in Castles

The first defenses to the cannon exploited its weaknesses, its slow rate of fire and immobility: wait until it fired, then run over and capture it.[Contamine 200] This worked well as long as the cannon was being used against personnell, but castles needed something more. As was done with the catapult and trebuchet before, the best defense to a cannon was another cannon. Every town and castle did their best to aquire gunpowder weapons and the materials to make them fire. [Contamine 201] The first record of a cannon in association with a castle comes from the first quarter of the fourteenth century. It tells of the cannon defending, rather than attacking, the castle.[Van Creveld 99] Defensive cannons were used right along with the traditional weapons:

Figure 1. Two details from a drawing of the seige of Althona in 1691. Top, bastions. Bottom, guns firing on zig-zagging trenches. [Van Creveld, 4th pictoral page after p118] Click on either of the pictures to see the full image.

From the middle of the fourteenth century the defence of castles was partially ensured by cannons, though doubtless of small calibre, taking their place along with crossbows, springalds and other engines. Thus at the castle of Bioule in 1347, according to an order of its lord, Hugues de Cardillac (or de Cardoullac), the 'gate in front of the place', among others, was to be defended in the following manner: 'On the first floor, two men to fire the cannons and throw the great stones; on the second floor, two men to fire the double-footed crossbow, then, on the wall, two crossbowmen, plus two men to throw fist-sized stones.' In total, 22 artillery pieces were to be used.[Contamine 202]

Changes in Castles

The layout of castles underwent a large change due to the power of gunpowder. Four major components were added:

• Blockhouses, low-lying towers in the moat, were added. These were placed all along the curtain to defend its base.[Contamine 203]
• The base of the wall was thickened, creating a sloped surface called a glacis.[Contamine 204]
• Towers along the curtain were shortened so that they could support the weight of the guns better, and to fascilitate the motion of ammunition. Located at the corners of the wall, these towers became known as bastions.[Contamine 204] Bastions were wedge-shaped, so that the gunners could have a clear field of fire along the base of the wall.[Van Creveld 103]
• Circular towers also became shorter, their sides were sloped and they were called roundels. Cannons could be positioned on top, as well as within the tower.[Van Creveld 102]

Sometime around 1520 - although certain forerunners can be traced as early as the 1470s or 1480s - the so-called "Italian" type of fortification emerged, a revolutionary innovation which had the effect of enormously strengthening the defense. First, the gradually increasing range of cannon caused fortifications to grow larger and more expensive. Second, they began to sprout outworks, which would make it more difficult for the attacker to bring his artillery within range. Initially these outworks consisted of isolated bastion-like structures so situated as to protect each of the star's points. However, it was not long before attempts were made to incorporate outworks and fortress into a single structure, which then led to the construc- tion of even further outworks. Over time, the process could repeat itself several times.[Van Creveld 103-4]