During Medieval times, it was common to construct castles and fortifications as a protection against enemy invasion. It was a common practice amongst kings all over the world to construct castles soon after conquering a country in order to solidify their hold on the new kingdom.
William the Conqueror had a string of castles constructed all over England after the Norman conquest of the country in 1066. Thus medieval castle defences played a very important role in the defence of the country and a kingdom with a batch of impenetrable castles had a clear edge over its enemies.
Like any defence mechanism, strategic locations were very important in medieval castle defences. The most important component in the defence was the location of the castle itself.
It was a common practice to construct the castle on high places such as mountain passes where it would be difficult for the enemy armies to attack. In actual defence, the walls of the castle served as the primary strategic location.
If the castle was located on plain land, it could be surrounded with a ditch of water to provide for solid defence.
Various defence tactics or methods were used for medieval castle defences.
For instance, it was common to construct castles of a circular shape which left no corners for miners of the enemy army to explore.
Another important tactic was to construct concentric castles with multiple walls which made invasion progressively difficult.
Finally, archers could shower arrows on the invading armies and stones and hot liquids could be poured over the approaching enemy if the walls were think and spacious enough.
There were various defensive parts of castles which served as strategic locations during invasions.
For instance, round towers were constructed because they provided a clear line of sight to the archers.
There were also slots in the walls that were used to shoot arrows through. These slots were called arrow loops and acted as an important component of medieval castle defences.
Among other defensive parts, there was an opening over the entrance to the castle known as murder hole which could be used to drop projectiles or burning liquids over the invaders.
During the early medieval ages, defending the castle was the responsibility of individual feudal lords who used their vessels to accomplish this.
This was true for the castles which did not have regular armies. In case of the latter, soldiers were responsible for the defence. Eventually, however, paid soldiers were used everywhere for medieval castle defences.
The soldiers were usually commanded by a constable who was responsible for the medieval castle defences in the absence of the owner.
Various weapons were prevalent for medieval castle defences.
The most important of these was the simple crossbow, considering the central role of archers in medieval castle defences.
One of the most important defensive devices designed during the high Middle Ages was a Trebuchet which, however, was mostly used against the fortifications instead of their defense.
Once the castle was penetrated and hand to hand battle ensued, common weapons of swords, spears, sling etc.were used.
Early medieval castles did not have the sophisticated defences of their later counterparts and were easier to attack and overrun, this led to constant improvements being made to keep pace with the advancements in medieval armoury and led to all round improvements in medieval castle defences and design.
In the later parts of medieval times with the invention of Gun-powder and Cannons Castles were fairly easy to destroy and the walls could easily be taken out, this and the new age of enlightenment at the start of the renaissance period led to the decline of Castles and this type of medieval warfare.