It is a system of living together for safety reasons.
Monarchs were very powerful people. They would get their power by ruling England.
Lords and Nobles were the ones to be responsible to manage and defend the manor.
A knight's job was to respect the lord's orders. And to become a knight there were three steps they had to follow throughout their lives and they were: Have many years of training, become a servant, and leave their home to go live in the manor's house