Comitatus, as described in the Roman historian Tacitus's treatise Germania (98.AD), is the bond existing between a Germanic warrior and his Lord, ensuring that neither leaves the field of battle before the other. The translation is as follows:
Comitatus, being the agreement between a Germanic lord and his subservients, is the direct source of the practice of Feudalism. Partly influenced by the Roman practice of a general distributing land to his officers after their retirement, the Germanic comitatus eventually evolved into a wholesale exchange between a social superior and inferior. The social inferior (in Feudalism, the Vassal) would pledge military service and protection to the superior (Lord). In return, the superior would reward the inferior with land, compensation, or privileges. [1]