ROME CREATED ONE OF THE LARGEST EMPIRES IN WORLD HISTORY. In its heyday, under the emperor Trajan in the second century AD, it governed up to 60 million people in an area of about 5 million square kilometres. It stretched from Spain to Turkey, from the Black Sea to the Maghreb, over what are now more than forty modern countries. Even so, in population and extent the Roman empire was easily surpassed by others—among them, the empires conquered by the British, the Mongols, the Russians, the Muslim Caliphs and the Spanish.
Where Rome wins out is in staying power. Its empire lasted as a single entity for more than 500 years, and its eastern half survived another millennium until the fifteenth century AD, when Muslim invaders brought it down. How did it manage this feat? The Romans were the most aggressive of people, and as they built their power, hardly a year passed when they were not at war with somebody. They acquired most of the then known world through conquest.
One would have thought this would have aroused resentment against their rule. But, having beaten up their victims, Romans shook them by the hand and invited them to join them as partners in the imperial project. Eventually every adult male living inside the frontier of this multicultural world became a Roman citizen. He was a stakeholder and stakeholders seldom revolt.*1