What are the characteristics of an empire?

The characteristics of an empire include a strong, centralized government. Empires throughout history have emanated from a central location or base of power from which it projected power outward. That central location was usually a city-state like Rome or a kingdom like existed in Spain. The ruling regime at that location invariably sought to capture ever-greater tracts of territory to exploit resources (including humans of different ethnicities to be forced into slavery) and to increase its stature as an empire.

Another characteristic of an empire is a large, relatively modernized military. That always meant an army of soldiers. In many instances, it also meant a sea-going fleet. Without that large military, expansion against the will of those already occupying the territory in question would be impossible, as would controlling that territory in years ahead—years that stretched in some cases (Rome, Ottoman) to centuries. These militaries were often equipped with forms of weaponry unheard of by those they conquered.

Empires were sought for the purpose of attaining natural resources, but they were also enormously expensive to maintain. In fact, they were so expensive to maintain that they sometimes drove the emperor or king into bankruptcy. Raising, equipping and feeding a large military is very expensive and the more battles or wars that had to be fought to expand or retain the empire further strained the central government or regime’s treasure.

An extension of the desire for resources and the need for a large military is the construction of the infrastructure necessary to move resources and goods from the conquered territories to the center and military forces to far-flung destinations. It is well-known that the Roman Empire was so successful in part because of its facility for constructing paved roadways that enabled more efficient movement of goods and people. As with the costs of the military, however, the costs associated with constructing and maintaining a network of roads, bridges and, where relevant, railroads, was and remains considerable.

The military keeps the peace and puts down insurrections, but an empire has to be administered by professional civil servants. That is another characteristic of empires: bureaucracy. Records have to be kept, expenditures tracked, personnel administered, payrolls maintained, and logistics managed. That has to be done by trained personnel knowledgeable about the territory being administered and the myriad issues that will invariably arise.

While an empire can be maintained that entails more than one currency, set of laws and disparate systems of enforcement, the more commonality across the board the more efficiently the empire can be managed. Not only does such commonality or standardization increase efficiency, it helps to control the empire. By imposing a single common currency, for example, the central regime can better control economic activity but can also better control the population of the empire.