A caste-based land ownership structure that existed throughout much of Europe between 800 and 1400 and that revolved around a multi-level hierarchy between lords (who held land granted under tenure from the king), and their tenants (also called "vassals").
Tenants would lease land from the lord in exchange for loyalty and goods or services, such as military assistance or money.
In exchange, the tenant would be protected from attack and have exclusive use of a deignated parcel of land.