Undoubtedly also through the influence of Roman institutions with which the Franks under their Merovingian kings came into close contact, there arose that social and political institution which became finally known as the _feudal system_. By the grants of lands which the kings made out of their estates to their kinsmen and followers with the understanding that they would be faithful and render service to their masters, a peculiar relationship grew up, based on land tenure, the land so granted being called a _fief_ or _feud_, and the relationship being called _vassality_ or _vassalage_. This vassalage denoted the personal tie between the grantor and grantee, the lord and the vassal; the lord having the obligation to defend the vassal, and the vassal to be a faithful follower of his lord. Similar relationship arose from the surrender by landowners of their estates to the church or to other powerful barons, to be received back again as fiefs and to be held by them as tenants in exchange for rent or service. In this way a complete organization of society developed in which, from the king down to the lowest landowner, all were bound together by obligation of service and defence, both the defence and service being regulated by the nature and extent of the fief. Finally, all kinds of property of whatever nature, as well as official positions which would give an income, were subject to be treated as fiefs. The obligations of the recipient were of various nature, but finally service in army or court became the main one, giving rise to the class of knights (_Ritter_) or barons, while the fiefs to the small farmer gave rise to the class of peasants (_Bauern_, this name appearing first in 1106 under Conrad II).
The fiefs of the higher class, while at first given only to the individual, became early hereditary, and hereditary succession to estates and offices generally became the rule. Primogeniture in the succession to the estates did then not as in England prevail in Germany; instead, either tenancy in common, or else equal division among the sons was practised. As a result the very many small principalities came into existence in the 14th and 15th centuries, these growing smaller and smaller by subdivision. The first to institute the primogeniture rule by law was the house of Brandenburg (in the 15th century).