FEUDALISM
In medieval Europe, the system for organising how land would be used and for controlling people was called the feudal system/feudalism, this was a matter of fact introduced by Charlemagne to Gaul (France) to help him gain control of large areas of land. As Charlemagne gained more land and becoming king in more countries progressed, this spread to more land in Central and Western Europe. William of Normandy conquered England after winning the battle of hastings and as England was already under the Feudal law, William took and was entitled taking and owning all the land. William then divided the land into parts and gave some of the land to people who had been trustful to him. This is an excellent example of how important feudalism was and how it could dramatically change peoples lives, at the click of your fingers. The feudal system had its perks and downs about it for people in different classes.
The diagram below explain what Feudalism is:
References-
http://en.wikipedia.org/wiki/Feudalism
http://en.wikipedia.org/wiki/Feudalism