Warriors nobles and feudalism

Feudalism is the name of the predominant political system in Western Europe in the middle centuries of the Middle Ages and Eastern Europe in the Modern Age, characterized by the decentralization of political power; to be based on the diffusion of power from the top (where in theory the emperor or the kings were) to the base where local power is actually exercised with great autonomy or independence by an aristocracy, called nobility, whose titles derived from governors of the Carolingian Empire (dukes, marquises, counts) or had another origin (barons, knights, etc.)

The term "feudalism" is also used to refer historiográficamente historical social formations characterized by the mode of production that historical materialism (Marxist historiography) called feudal.

In the Middle Ages, the institution of chivalry was related to a code of conduct and honor that defined not only the art of war, but also implied social behavior.
To arm and mount a warrior is very expensive, so medieval chivalry appears fully linked to the phenomenon of feudalism. Knights are lords or advantaged subjects with social and economic power, also keep the exclusivity of the cavalry to his class. Initially protected with a full suit of chainmail (Coif, brafoneras and breastplate) and a helmet that grows in size to become the twelfth century in a large, heavy metal bucket resting on his chest and back.