When Rome had collapsed the world had went into the middle ages. In the middle ages most of Europe was divided between lords and princes. They would rule the more local land and the people who lived on it. In order to defend themselves they built their homes as castles. These were in the center of the land that they ruled. They could defend from attacks and even prepare to launch attacks from their own castles. These castles were originally made of timber and wood. Later on they were replaced with stone to be stronger. Castles were sometimes built on hills but, most of the time they were built in the best place for defence. After the middle ages castles weren't built as much. More weapons were built that can take down the whole