A form of conglomerate state encompassing a geographical area or set of areas containing diverse peoples or ethnic groups and ruled by a single central government authority that is primarily identified with one dominant people or ethnic group. The empire thus consists of an imperial center and one or more colonies or other dependent subunits (provinces, protectorates, etc.) whose governments are subordinate to that of the imperial center. Historically, empires have usually first emerged either as the result of dynastic marriages among the royal families of hereditary absolute monarchies or, even more frequently, by an original "core" state expanding through the conquest and incorporation of territories occupied by other peoples, usually followed by the resettlement of substantial numbers of emigrants from the core population who then constitute a privileged governing elite in the newly acquired territories. An empire differs from such other forms of conglomerate state as a federation or confederation by virtue of the specially privileged political status of the core political unit (and often the entire core ethnic group or race) in contrast to the institutionalized inferior status of the other component governmental units and their native populations.