Empire - Multiple states under one central authority

"An empire is a sovereign state functioning as an aggregate of lands and peoples that are ruled over by an emperor-like monarch or oligarchy. The territory and population of an empire is commonly of greater extent. History's largest empires, such as the Roman, British and Mongol empires, were typically characterized by the conquest, colonization, plunder, and subordination of often large numbers of territories, kingdoms, ethnicities, and nations, for the benefit of the empire's central rulers and economic elites. - Wikipedia"