After the collapse of Western Modern Empire, it became very difficult to manage the law and order situations in the smaller kingdoms initiated by the Barbarians. Evolution and spread of religious movements of Christianity and Islamism further complicated the situations. In order to ascertain security of their kingdoms, kings preferred to transfer power to knights and barons. Ordinary people, peasants and serfs accepted their rule to attain protection against invaders and rival kingdoms. This situation gave way to the rise of feudalistic law and justice system. - See more at: http://www.thefinertimes.com/Middle-Ages/law-in-the-middle-ages.html#sthash.rvcJPrQT.dpuf