Medieval castles were formidable structures designed to protect their inhabitants from attackers and to serve as symbols of power and authority. However, these fortifications also faced numerous threats, leading to the development of sophisticated techniques for both attacking and defending these strongholds. Understanding the strategies and technologies used in medieval castle warfare provides a fascinating insight into the military and architectural ingenuity of the time.
Attacking Medieval Castles
Attacking a medieval castle was no small feat, as these fortifications were designed with defence in mind. However, there were several effective strategies that attackers could employ to breach a castle’s defences:
Starvation (Siege Warfare):
One of the most common strategies for attacking a castle during medieval times was to lay siege to it, a method that involved surrounding the castle and cutting off all supplies, particularly food and water, in an effort to starve the defenders into submission. This approach required patience and meticulous planning, often turning into a lengthy ordeal. Starvation was particularly effective against castles that were geographically isolated and could be easily surrounded; however, its success diminished if the castle had access to a river or the sea, which allowed for the potential of resupplying or evacuating the garrison. A notable example of this strategy’s effectiveness is the Siege of Kenilworth Castle in 1266, during the Second Barons’ War, which became one of the longest sieges in English history, lasting nearly six months before the defenders surrendered due to starvation.
Mining (Undermining):
Mining was a strategic method of attacking a castle by digging tunnels under its walls to weaken their foundations. Once the tunnels were directly beneath the walls, they were filled with flammable materials and set ablaze, causing the tunnel to collapse and the walls above to crumble, creating a breach for attackers. However, this approach was labour-intensive and dangerous, often countered by defenders who dug counter-tunnels to intercept and fight the miners. Castles built on solid rock or protected by water-filled moats were particularly resistant to such attacks. A notable example of this strategy occurred during the Siege of Dover Castle in 1216, where attempts to undermine the walls ultimately failed but demonstrated the potential vulnerability of even the strongest fortifications to determined mining efforts.
Treachery, Surprise, and Stupidity:
Not all castles were captured through direct assault; sometimes, treachery or mistakes by the defenders played a crucial role in their downfall. This could involve bribing a guard to open a gate or seizing an opportunity when the defenders were careless. For instance, in 1204, the French captured Chateau Gaillard after discovering an unguarded chapel window, which allowed a small force to enter the castle and open the gates from within. Similarly, during the Albigensian Crusade, the city of Béziers fell when the defenders rashly opened the gates for a sortie, leaving their entrance undefended and allowing the attackers to seize the city.
Siege Engines:
Trebuchets were amongst the most powerful siege engines of the medieval period, capable of hurling massive stones over great distances to batter down walls or wreak havoc within a castle’s defences. Although their construction required significant time and resources, their impact could be devastating. Battering rams, used to break down gates and doors, were often shielded by protective sheds to safeguard operators from arrows and boiling oil. To counter these, some castles featured sloped skirts at the base of their walls, designed to deflect or neutralise the rams’ impact. Siege towers, on the other hand, were mobile structures that enabled attackers to scale high castle walls while staying protected from defensive fire. Once the top of the tower reached the level of the battlements, soldiers could storm across onto the walls, engaging defenders in close combat.
Storming the castle
Storming a castle was one of the most direct and perilous methods of siege warfare, involving a full-scale assault on the fortress’s walls and defences. This strategy often required overwhelming numbers of attackers to climb ladders, breach gates, or force their way through openings created by other siege engines like battering rams or trebuchets. The assault would typically begin with a barrage of projectiles from archers or siege weapons to weaken the defenders, followed by waves of soldiers attempting to scale the walls or break through the defences. Storming a castle was a high-risk approach, as attackers were exposed to a deadly array of defensive measures, including arrows, boiling oil, rocks, and other projectiles. Despite the risks, if successful, storming could lead to the rapid capture of a castle, often before the defenders had the chance to regroup or reinforce their positions.
Defending Medieval Castles
Defending a medieval castle required careful planning, ingenuity, and the ability to make the most of the castle’s natural and man-made features. Here are some of the key strategies employed by defenders:
Location and Terrain:
Strategic positioning was one of the most crucial elements of a castle’s defence, beginning with its location. Castles were often built on elevated ground, such as hills or cliffs, which made them difficult to assault. Natural barriers like rivers, marshes, or steep cliffs further enhanced a castle’s defences, hindering both mining and direct assaults. For example, the towering cliffs of Mont-Saint-Michel in Normandy rendered the castle nearly impregnable. Attackers had to contend with the challenging tides and the steep, treacherous ascent, making any direct assault a formidable task.
Castle Design and Architecture:
Concentric castles were formidable defensive structures, featuring multiple layers of walls, each within the other, providing successive lines of defence. Even if attackers managed to breach the outer wall, they would still face additional walls to overcome, making the castle increasingly difficult to capture. Round towers were another key defensive feature, as their circular design eliminated the dead corners that attackers could exploit. The rounded shape also made it easier to deflect missiles and posed greater challenges for miners attempting to tunnel beneath. Moats and water defences added yet another layer of protection; these barriers, whether dry or filled with water, made it difficult for attackers to bring siege engines close to the walls and also hindered tunnelling efforts. Some castles, like Caerphilly Castle, had sophisticated water defenses, such as sluice gates, which allowed defenders to flood the surrounding area, further complicating an attack.
The Castle Gatehouse:
The gateway was typically the most vulnerable point of a castle, necessitating extensive fortifications to protect this critical entry. Defenders relied on multiple layers of security, including drawbridges, portcullises, and heavy wooden doors. To breach the castle, attackers first had to lower the drawbridge, force their way through the portcullis, and then overcome the heavily fortified main gate. Adding to this defence, many castles featured a barbican, a fortified outpost or gateway situated in front of the main entrance. The barbican served as the first line of defence, creating a killing ground where attackers could be trapped and subjected to crossfire from multiple directions, making it an effective deterrent against enemy assaults.
Active Defences:
Arrow slits and murder holes were essential defensive features in medieval castles. Arrow slits were narrow openings in the walls that allowed archers to fire arrows at attackers while staying protected. Murder holes, typically located above gates or passageways, enabled defenders to drop boiling oil, rocks, or other projectiles onto attackers attempting to breach the castle. Machicolations, stone projections at the top of walls and towers, served a similar purpose, with openings that allowed defenders to drop stones or hot liquids directly onto besiegers at the base of the walls. Meanwhile, battlements, with their alternating high and low sections (crenellations), provided cover for archers and crossbowmen, enabling them to fire at attackers while minimising their exposure to return fire. These defensive features worked together to create a formidable barrier against any assault.
Psychological Warfare:
Defenders often employed psychological tactics to sow dissent among attackers, aiming to demoralize them and weaken their resolve. This could involve gruesome displays, such as showing the heads of captured enemies, or spreading rumors of reinforcements on the way. These strategies were designed to instil fear and doubt in the besieging forces. In some cases, the threat of a prolonged siege or the potential arrival of a relief force was enough to prompt attackers to consider parley and negotiation. Aware of the costs and risks of continued conflict, attackers might agree to withdraw or surrender under certain terms. Similarly, defenders, if faced with an untenable situation, might choose to surrender under favorable conditions, believing it was their best option to avoid further loss. These exchanges highlighted the strategic use of psychological warfare and diplomacy in medieval sieges.
Castles and Strategic Warfare
Medieval castles were more than just defensive strongholds; they were also key elements in broader military and political strategies. Their placement was carefully chosen to control vital trade routes, dominate surrounding territories, and assert the authority of the ruling lord or king.
Military Control:
Controlling territory through a network of strategically placed castles was a key strategy for medieval rulers to maintain authority over vast areas. By constructing castles at critical points, such as river crossings, mountain passes, or along the coast, rulers could secure their borders, monitor trade routes, and oversee their lands more effectively. This network not only provided defense but also allowed for the swift movement of troops and supplies across the territory. In some instances, castles were deliberately built to divide and weaken invading forces. By forcing attackers to lay siege to multiple castles simultaneously, defenders could stretch the enemy’s resources thin, buy valuable time, and prevent them from concentrating their forces. This divide and conquer strategy made it difficult for invaders to achieve a decisive victory, often leading to prolonged and costly campaigns.
Symbol of Power:
Imposing structures like castles served as powerful symbols of authority and dominance. The sight of a massive stone fortress towering over the landscape sent a clear message to any would-be rebels or invaders about the ruler’s strength and control. These castles were not just military fortifications; they were statements of power. Over time, many castles became the nucleus of thriving communities, with towns developing around them. The protection offered by the castle attracted settlers, and as these towns grew, the castle evolved into both a military stronghold and an administrative centre. This intertwining of town and castle created a symbiotic relationship, where the castle provided security, and the town contributed to the economic and social life of the region.
Economics and Trade:
Castles strategically placed along trade routes or at river crossings allowed lords to collect tolls and taxes from merchants and travellers, providing a steady source of income and reinforcing their control over the region’s economy. This practice not only generated revenue but also asserted the lord’s dominance over key economic activities. Additionally, castles played a crucial role in controlling local resources such as farmland, forests, and mines. By securing these resources, the castle’s lord could ensure the economic stability and prosperity of his domain, further solidifying his power and influence in the region.
Conclusion
The defence and attack of medieval castles were complex and multifaceted operations that required a combination of military strategy, engineering, and psychology. Castles were designed not only to withstand sieges but also to project power and control over the surrounding lands. Understanding the methods used in both defending and attacking these fortresses reveals much about the nature of medieval warfare and the importance of castles in the social and political fabric of the Middle Ages.