This section is from the book "Popular Law Library Vol1 Introduction To The Study Of Law Legal History", by Albert H. Putney. Also see: Popular Law-Dictionary.
The most important institution in Europe during the Middle Ages was feudalism. It is around this system that, for about eight centuries, the history of Western Europe is centered. It is this wide extent of feudalism, measured both by time and by space, that makes any satisfactory definition of this institution so difficult. Feudalism is never stationary. There is the period of its development, the period of its greatest power, and the period of its decline. The feudalism of one country during one century will be found very different from that of another country in another century.
Feudalism also presents a varying picture in accordance with what phase of the subject we are considering. Feudalism is at the same time a system of land ownership; a personal relation between lord and vassal; and the basis for the military organization of the times; by it are determined the political, social, and economic status of every inhabitant of the country.
The oldest aspect of feudalism is the military one. The most uniform and important characteristic of feudalism is the existence of the relation of lord and vassal, which made possible the organization of effective military forces. Effective military forces in the middle ages meant conquest, and conquest meant land to be divided among the victors. It only becomes necessary to make the holding of such land by the vassals dependent upon continued military service to the lord, to have a feudal system of land tenure. For the great body of the men of the middle ages, the only occupations possible were those of agriculture or war; with both of these thoroughly feudalized, every man's position in the social and economic structure must be determined by the workings of this system.
1 Pollock and Maitland's History of English Law. Volume I., pp. 66 and 67, 1st Edition.
One great result of feudalism was the substitution of the idea of territorial Jaws for the systems of racial laws previously prevailing in Europe.