It provided protection and security (But not much.) for tenants (lower class) who either only wanted to or could only farm the land. This provided a hefty percentage of what was work to the Lord (upper class) of that land and the knights that provided protection. read more
In its initial stages, feudalism was important because it helped William I to earn the loyalty and specific services from noblemen who had served in his army. This system was established by William I because he was not popular and influential among the people of England. read more