There have been more or less 7 great dominant empires in the world: in rough chronological order.
Egypt (Late Kingdom)
Greece (okay, I know Alexander was Macedonian)
China (Han, Tang, or Ming dynasties)
Rome (this should be obvious, under Augustus Caesar)
Arabia (The Abbasid Caliphate around 800-1000 AD)
Britain (1880 or so)
America (present day)
Egypt (Late Kingdom)
Greece (okay, I know Alexander was Macedonian)
China (Han, Tang, or Ming dynasties)
Rome (this should be obvious, under Augustus Caesar)
Arabia (The Abbasid Caliphate around 800-1000 AD)
Britain (1880 or so)
America (present day)