Scholars debate what exactly constitutes an Empire (from the Latin "imperium", denoting military command within the ancient Roman government). Generally, they may define an empire as a state that extends dominion over areas and populations distinct culturally and ethnically from the culture/ethnicity at the center of power. Other definitions may emphasize economic or political factors. The term generally implies military hegemonic power. (The United States, for example, currently rates as an economic, cultural, and political empire, as its influence extends across the world; however, debate may occur as to whether it resembles a militaristic empire.)Achaemenid Empire Seleucid Empire Ottoman Empire Roman Empire Persian Empire Byzantine Empire
