The political power of the Carolingian rulers had long rested on the cooperation of the dominant social class, the Frankish aristocracy. Charlemagne and his predecessors relied on the nobles to help wage wars of expansion and suppress rebellions, and in return these families were given a share of the lands and riches confiscated by the rulers. The most powerful nobles were those able to gain the allegiance of warriors, often symbolized in an oath-swearing ceremony of homage and fealty that grew out of earlier Germanic oaths of loyalty. In this ceremony a warrior (knight) swore his loyalty as a vassal — from a Celtic term meaning “servant” — to the more powerful individual, who became his lord. In return for the vassal’s loyalty, aid, and military assistance, the lord promised him protection and material support. This support might be a place in the lord’s household, but was more likely a piece of land called a feudum or fief (feef). In the Roman Empire, soldiers had been paid for their services with money, but in the cash-poor early Middle Ages, their reward was instead a piece of land. Most legal scholars and historians have seen these personal ties of loyalty cemented by grants of land rather than allegiance to an abstract state as a political and social system they term feudalism. They have traced its spread from Frankish areas to other parts of Europe.

In the last several decades, increasing numbers of medieval historians have found the idea of a “feudal system” problematic. They note that the word feudalism was a later invention, and that vassalage ceremonies, military obligations, and the ownership rights attached to fiefs differed widely from place to place and changed considerably in form and pattern over time. Thus, to these historians, “feudalism” is so varied that it doesn’t really have a clear meaning, and it would be better not to use the term at all. The problem is that no one has come up with a better term for the loose arrangements of personal and property ties that developed in the ninth century.

Whether one chooses to use the word feudalism or not, these relationships provided some degree of cohesiveness in a society that lacked an adequate government bureaucracy or method of taxation. In fact, because vassals owed administrative as well as military service to their lords, vassalage actually functioned as a way to organize political authority. Vassals were expected to serve as advisers to their lord, and also to pay him fees for important family events, such as the marriage of the vassal’s children.

Along with granting land to knights, lords gave land to the clergy for spiritual services or promises of allegiance. In addition, the church held its own lands, and bishops, archbishops, and abbots and abbesses of monasteries sometimes granted fiefs to their own knightly vassals. Thus the “lord” in a feudal relationship was sometimes an institution. Women other than abbesses were generally not granted fiefs, but in most parts of Europe daughters could inherit them if their fathers had no sons. Occasionally, women did go through ceremonies swearing homage and fealty and swore to send fighters when the lord demanded them. More commonly, women acted as surrogates when their husbands were away, defending the territory from attack and carrying out administrative duties.

Some of the problems associated with the word feudal come from the fact that it is sometimes used by nonhistorians as a synonym for “medieval,” or to describe relations between landholders and the peasants who lived and worked on their estates. (The latter use comes from Karl Marx, who used “feudalism” to describe a stage of economic development between slavery and capitalism.) Medieval historians on all sides of the debate about feudalism agree, however, that peasants did not swear oaths of vassalage; if there was a feudal system, peasants were not part of it.