Under the system of feudalism, a fiefdom, fief, feud, feoff, or fee, often consisted of inheritable lands or revenue-producing property granted by a liege lord, generally to a vassal, in return for a form of allegiance, originally to give him the means to fulfill his military duties when called upon. However anything of value could be held in fief, such as an office, a right of exploitation (e.g., hunting, fishing) or any other type of revenue, rather than the land it comes from.
Originally, the feudal institution of vassalage did not imply the giving/receiving of landholdings (which were granted only as a reward for loyalty), but by the eighth century the giving of a landholding was becoming standard. The granting of a landholding to a vassal did not relinquish the lord's property rights, but only the use of the lands and their income; the granting lord retained ultimate ownership of the fief and could, technically, recover the lands in case of disloyalty or death. By the middle of the tenth century, fiefs had largely become hereditary. Eventually, great feudal lords sought also to seize governmental and legal authority (the collection of taxes, the right of high justice, etc.) in their lands, and some passed these rights to their own vassals.
In contemporary usage, fiefdomism can refer to behavior of bureaucrats or small time politicians when information or programs are isolated and jealously guarded from other bureaucrats or small time politicians in order to preserve their power at the expense of making government worse.