Feudal law describes a political system which placed men and estates under the hierarchical distinctions of "lords" and "vassals". Feudalism refers to the relations and interdependence between lord and vassal, based on the fief, or ownership of land.

The principal feature of this system was:

The right to all lands was vested in the sovereign, or king.

Lands were parcelled out amongst the great men of the nation, so that the king had the dominum directum, and the grantee or vassal had what was called dominum utile. The land became known as a "fief", or fiefdom. The maxim ran nulle terre sans seigneur. Those great men, as vassals to the king, became known as "lords."

These tenants or vassals were bound to perform services to the king, usually as members of the king's army. These great lords again granted parts of the lands they thus acquired, to other inferior vassals, who held under them and were bound to perform services to the lord.

The principle went all the way down from those great lords to the lowly knight, with any number of levels in between, depending on the local circumstances. In theory, nobody really owned the land, all being a vassal to a higher noble, with the king or the emperor holding the property in trust for the divinity.