Norman rule was kept controlled by both castles and the feudal system. Castles were built high to both emphasise their authority against the village by being above them, almost God-like, and additionally to watch over and see for attacks. The feudal system went from Kings, to Nobles, to Knights, to Peasants and that was the order in status of the Norman society, etc - the peasants would receive land from the Knights but also have to work for them so they have to work but get something in return.