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.