Feudal society is a sometimes-debated term used to describe the social order in the Western Europe, Central Europe, and sometimes Japan and other regions in the Middle Ages, characterized by the legal subjection of a large part of the peasantry to a hereditary landholding elite exercising administrative and judicial power on the basis of reciprocal private undertakings.
The term's validity is questioned by many medieval historians who consider the description "feudal" appropriate only to the specifically voluntary and personal bonds of mutual protection, loyalty and support among members of the administrative, military or ecclesiastical elite, to the exclusion of involuntary obligations attached to tenure of "unfree" land. This stricter concept is discussed under feudalism, and the bonds which it excludes under manorialism. Examples of feudalism are helpful to fully understand feudalism and feudal society.
Alongside such broad similarities, it is important to note the divergences both within and between feudal societies (in forms or complexity of noble association, the extent of peasant dependency or the importance of money payments) as well as the changes which occurred over time within the overall structure (as in Bloch's characterisation of the 11th-century onset of a "second feudal age").
In particular, one should avoid envisaging the social order in terms of a regular "feudal pyramid" with each man bound to one superior lord and the rank of each clearly defined, in a regular chain of allegiances extending from the king at the top to the peasantry at the bottom: aside from the contrast between free and unfree obligation, allegiance was often given to more than one lord, while an individual might possess attributes of more than one rank.
Nor should the medieval theory of the "estates of the realm" or the "three orders" of feudal society—"those who make war" (miles, knights), "those who pray" (priests, monks) and "those who labour" (peasants, serfs)" (bellatores, oratores, et laboratores)—be considered a full description of the social order: while those excluded from the first two came over time to be counted among the third, nobles and clerics alike assumed administrative functions in the feudal state, while financial support was relied upon increasingly as a substitute for direct military service. Nobles were defined by the occupation they obtained and no longer by right of birth and are placed in power by the investiture.
The values of men who fought under the first of the "three orders" were first his horse, second his son, and third his wife. A soldier's horse, in feudal society, was considered the price of two and a half generations or two men and a boy. The role of women consisted of maintaining the household economy: controlled peasants and regulating what crops will and will not be grown and sold.
"Those who prayed" consisted of priests, monk, and other authorities of the church. The church willingly supported the three orders. "Those who work," peasants and serfs, consisted of the majority of the population and suffered the most.
While few would deny that most of France, England, parts of Spain and the Low Countries, western and central Germany and (at least for a time) northern and central Italy satisfied Bloch's criteria over much of the period, the concept remains of greatest use as an interpretive device for comparative study of local phenomena, rather than as a blanket definition of the medieval social order.
European medieval feudal society evolved into its most recognised in the northern French heartland of the Carolingian monarchy of the 8th-10th centuries, but has its antecedents also in late Roman practice. It reached it most developed state in 11th and 12th century, particularly in northern France, England, the Norman principalities of southern Italy and, to a lesser extent, in Germany. It also appears to have taken on a highly developed form in the Latin crusader states.
As more infrastructure is added more people come to owe their sustenance to the king. Specialists in surveying, drafting deeds, digging, planting, building, tool making, the domestication of beasts of burden, all come to have standards and status for the practice of their professions. Their entitlement to the land isn't directly from service to the king but to the people who hold the land in return for their service to the king.
As things get more complicated the primary role of the king becomes the administration of the system. The social order becomes hierarchical. Trade with other similar kingdoms begins to require agreed upon standards, of behavior and laws regarding commerce and the ownership of property.