Castles only began to be built in England after the Norman Conquest. The Normans built many to secure areas where they faced resistance, but they also built castles as a show of strength. The first castles were made of earth and wood, and could be built extremely quickly.
The most common early type was the
Motte and Bailey castle. These castles consisted of a wooden
fort on top of a man-made mound (motte) with an enclosed surrounding
area (bailey) defended by a tall wooden fence (palisade). A
small community could live inside the bailey. Ditch and bank
defences surrounded the Motte and Bailey.
During the 12th century many castles were improved and strengthened using stone instead of wood. Many ideas for improving defences came from the east. Concentric castles from the later middle ages show this.
These castles had one walled enclosure built inside another. More complicated designs saw more and more walled enclosures inside one another, each improving the strength of the castle even more. Edward I used castles like this to secure his position in Wales.
As new methods of warfare developed (such as the use of the cannon) the importance of the castle changed. They rapidly became status symbols rather than having military importance. Some historians argue that many castles were never anything but status symbols, and the Norman use of castles to show strength may suggest this.