The reason the Romans were able to maintain their empire for centuries as opposed to Alexander (and his descendents) or the Athenians is that the Romans instituted government and legislation that protected those they conquered. As a result, those who were enveloped into Roman dominion were also enveloped into secondary Roman citizenship, enjoying the provisions and protection prescribed by Rome to its conquered territories.
Over a thirteen year reign Alexander and his successors conquered and destroyed dozens of Greek city states all across the eastern Mediterranean. Before long, Alexander established a vast empire and controlling it proved to be more difficult than expected. Both Alexander and the Athenians did not have any set laws within their empires regarding appropriate treatment of conquered territories which is the main reason for their failure. In the absence of legislation to protect the welfare of conquered territories, their inhabitants were left with little hope and were easily quarried into rebellion. Rulers wielded absolute power and lorded over the entire community they ruled. Conquering kings were worshiped, either voluntarily or by force. They were often considered to be gods, with absolute privilege to anything and anyone that fell into their dominion. The wealthy dominated the societies and government while the conditions of the poor worsened. They often sold the citizens of conquered cities into slavery, denying them of all rights and liberties. Empires prior to Rome often forced their culture and religion upon those they conquered, a situation that would be absolutely intolerable to many. Previous empires also commonly instituted severe taxation upon conquered territories, yet again worsening the living conditions of these territories. Alexander and the Athenians were not
able to hold onto their empires for the obvious reasons shown; after taking control of a region, they left its inhabitants in such a dire situation that...