The term empire comes from the Latin imperium. Politically, an empire's 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… (More on Empire)