Unfortunately this construct did not account for variations over time and region, nor for the fact that the feudal relationship was really a relationship between people, and could vary with one person to the next. Nor did it allow for one person's vowing allegiance to more than one other person. It was a nice model, but was only that. It bore no strong resemblance to historical reality. As such, Brown advocated throwing the entire terminology out.
Most historians have offered a more mediatory approach. It is that approach that follows.
Extant sources reveal that the early Carolingians has vassals, as did other leading men in the kingdom. This relationship did become more and more stardardized over the next two centuries, but there were differences in function and practice in different locations. For example, in the German kingdoms that replaced the kingdom of Eastern Francia,as well as in some Slavic kingdoms, the feudal relationship was arguably more closely tied to the rise of serfdom, a system that tied peasants to the land (for more on this see the works of Leonard Blum on the history of serfdom). Moreover, the evolution of the Holy Roman Empire greatly affected the history of the feudal relationship in central Europe. If one follows long-accepted feudalism models, one might believe that there was a clear hierarchy from Emperor to lesser rulers, be they kings, dukes, princes, or margraves. These models are patently untrue: the Holy Roman Emperor was elected by a group of seven magnates, three of whom were princes of the church, who in theory could not swear allegiance to any secular lord.
The French kingdoms also seem to provide clear proof that the models are accurate, until we take into consideration the fact that, when Hrolf or Rollo the Gangler kneeled to pay homage to [Charles the Simple]? in return for the Duchy of Normandy, accounts tell us that he knocked the king on his rump as he rose, demonstrating his view that the bond was only as strong as the lord -- in this case, not strong at all. The autonomy with which the Normans ruled their duchy supports the view that, despite any legal "feudal" relationship, the Normans did as they pleased. In the case of their own leadership, however, the Normans utilized the feudal relationship to bind their followers to them. It was the influence of the Norman invaders who strengthened and to some extent institutionalized the feudal relationship in England after the [Norman Conquest]?.
One can never deny that the accepted characteristics of feudalism existed throughout much of the middle ages. However, because those characteristics cannot be shown to have been truly systematized, we must take great care in how we use the terms "feudal" and "feudalism." The use of these terms depends so heavily upon context, that that context should always be given, except in the very narrow sense of an oath-based personal relationship in which one person promises armed support and faithfulness to another in exchange for support in the form of lands or wealth.