Feudal duties were the set of reciprocal financial, military and legal obligations among the warrior nobility in a feudal system. These duties developed in both Europe and Japan with the decentralisation of empire and due to lack of monetary liquidity, as groups of warriors took over the social, political, judicial, and economic spheres of the territory they controlled. While many feudal duties were based upon control of a parcel of land and its productive resources, even landless knights owed feudal duties such as direct military service in their lord's behest. Feudal duties were not uniform over time or across political boundaries. And in their later development also included duties from and to the peasant population, such as abergement. Feudal duties ran both ways, both up and down the feudal hierarchy; however, aside from distribution of land and maintenance of landless retainers, the main obligation of the feudal lord was to protect his vassals, both militarily from incursion and judicially via court justice. In addition to lands, the lord could grant what were called "immunities", but were rights to conduct governmental functions such as the collecting of taxes and tolls, the holding of judicial proceedings, and even the coinage of money. In addition there were contingent duties the lord owed such as the duty to take back a fief that was rejected by an heir. Sometimes, particularly in the Frankish kingdoms, a lord would grant a fief to an assemblage of men rather than to a single vassal. These grants were called bans and included extensive governmental autonomy, or immunities. Duties owed by a vassal to his lord can be categorised into four types:
Military, which included personal service, providing troops, and later scutagein lieu of service. Military duties also included work on fortifications and roads and bridges, thus the trinoda necessitas.
Court duties, which encompassed everything from security through rendering advice in council, providing squires and even in some cases providing de facto hostages.
Special taxes, often called feudal aids, were monies due upon certain contingent events, such as contributing to the lord's ransom, or to pageant-like events at court such as royal marriages.
Incidents, which included such things as a negotiated kickback to the lord upon being granted a fief, the duty to feed and house the lord and his retinue when the lord visited, allowing the lord to hunt or fish on his land and being subject to the residual lordly rights of guardianship upon minority inheritance, and forfeiture upon a failure of heirs or failure to observe his feudal obligations.
In Europe, church lands were also held with feudal duties. While some churchmen did provide direct military service, most either hired substitutes, paid scutage, or later converted the duty to one of prayer, frankalmoin.
