Castle Architecture

Common features:

 

Motte - an earthen mound with a flat top. The excavation of earth to make the mound left a ditch around the motte which acted as a further defence. It was common for the motte to be accessed via a flying bridge.

 

Bailey and enceinte 

A bailey, also called a ward, was a fortified enclosure. It was a common feature of castles, and most had at least one. The keep on top of the motte was the domicile of the lord in charge of the castle and a bastion of last defence, while the bailey was the home of the rest of the lord's household and gave them protection. The barracks for the garrison, stables, workshops, and storage facilities were often found in the bailey.

From the late 12th century there was a trend for knights to move out of the small houses they had previously occupied within the bailey to live in fortified houses in the countryside.

 

Keep - a great tower and usually the most strongly defended point of a castle before the introduction of concentric defence. Although often the strongest part of a castle and a last place of refuge if the outer defences fell, the keep was not left empty in case of attack but was used as a residence by the lord who owned the castle, or his guests or representatives. The massive internal spaces seen in many surviving donjons can be misleading; they would have been divided into several rooms by light partitions, as in a modern office building. Even in some large castles the great hall was separated only by a partition from the lord's "chamber", his bedroom and to some extent his office.

 

Curtain walls - defensive walls enclosing a bailey. They had to be high enough to make scaling the walls with ladders difficult and thick enough to withstand bombardment from siege engines which, from the 15th century onwards, included artillery. Walkways along the tops of the curtain walls allowed defenders to rain missiles on enemies below, and battlements gave them further protection.

 

Gatehouse

The entrance was often the weakest part in a circuit of defences. To overcome this, the gatehouse was developed, allowing those inside the castle to control the flow of traffic. The front of the gateway was a blind spot and to overcome this, projecting towers were added on each side of the gate in a style similar to that developed by the Romans.The gatehouse contained a series of defences to make a direct assault more difficult than battering down a simple gate.

 

Moat - a defensive ditch with steep sides, and could be either dry or filled with water. Its purpose was twofold; to stop devices such as siege towers from reaching the curtain wall and to prevent the walls from being undermined. Water defences, such as moats or natural lakes, had the benefit of dictating the enemy's approach to the castle

 

Other features

Battlements were most often found surmounting curtain walls and the tops of gatehouses, and comprised several elements:

• crenellations - iternating crenels and merlons: gaps and solid blocks on top of a wall
• Hoardings - wooden constructs that projected beyond the wall, allowing defenders to shoot at, or drop objects on attackers at the base of the wall without having to lean perilously over the crenellations, thereby exposing themselves to retaliatory fire.
• Machicolations - stone projections on top of a wall with openings that allowed objects to be dropped on an enemy at the base of the wall in a similar fashion to hoardings.
• Loopholes/Arrowslits - narrow vertical openings in defensive walls which allowed arrows or crossbow bolts to be fired on attackers.

 

Development of gunpowder affected castle architecture.

Bigger guns were developed, and in the 15th century became an alternative to siege engines such as the trebuchet. By the 1450s guns were the preferred siege weapon. The response towards more effective cannons was to build thicker walls and to prefer round towers, as the curving sides were more likely to deflect a shot than a flat surface.
http://en.wikipedia.org/wiki/Castle