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Empire from WikiPedia:

The term empire derives from the Latin imperium. Politically, an empire is a geographically extensive group of states and peoples (ethnic groups) united and ruled either by a monarch (emperor, empress) or an oligarchy. Geopolitically, the term empire has denoted very different, territorially-extreme states — at the strong end, the extensive Spanish Empire (16th c.) and the British Empire (19th c.), at the weak end, the Holy Roman Empire (8th c.–19th c.), in its Medieval and early-modern forms, and the Byzantine Empire (15th c.), that was a direct continuation of the Roman Empire, that, in its final century of existence, was more a city-state than a territorial empire.

Etymologically, the political usage of “empire” denotes a strong, centrally-controlled nation-state, but, in the looser, quotidian, vernacular usage, it denotes a large-scale business enterprise (i.e. a transnational corporation) and a political organisation of either national-, regional-, or city scale, controlled either by a person (a political boss) or a group authority (political bosses).

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