William’s conquest had as a consequence an incredible concentration of the entire wealth of the country into the hands of very few families(king and aristocracy). Within 1085 William had given out a quarter of the total landed wealth of England to no more than 12 families. Another quarter was directly held by the king himself while a further quarter was assigned to the church. He declared that the true owner of all the lands was the king himself. These are the foundations of the future feudal system.
It was organized/developed through a precise hierarchical management/order/hierarchy which foresees as the true owner of all the lands the king himself who is at the top of the pyramid and had in his possession all the lands. Anyway who actually held and actually organized the king’s landed wealth and assured the cultivation of the lands were the king’s vassals: the barons. The king assigned most of his possessions to vassals, who had to cultivate such lands, not personally. In exchange for their services they received a part of the produce of the land/crop and they had to promise to serve the king in war. These barons, nobles, vassals in their own turn gave parts of the lands to the knights or freemen who supplied military services and in some cases they had to pay a rent . Who actually cultivated the lands were the serfs, slaves or peasants, the last link of the social chain (they saved a part of the produce for themselves but they couldn't leave the lands, they weren't free).
Consequences of feudal system
Feudal system resulted in a strong concentration of the wealth of the country into the hands of aristocracy. From an economic point of view, such a concentration of wealth into the hands of few families resulted in a social gap: only few families became extremely rich, while most of the population was incredibly poor (Anglo Saxons lived as equals and didn't have private property). There was an economical-social gap between the conditions of life of the lower social strata and the ones of the upper social strata.