Empires as systems

Empires are complex political communities where a central group had some form of control over the governance of peripheral (outside) groups. The difference and relationships between these two groups are what made the state an empire, rather than a kingdom. A third group that could affect an empire’s power was the people who lived just beyond its border. Often these border regions were inhabited by nomadic or semi-nomadic tribal peoples, typically seen as barbarians by the empires. Sometimes the border could be shared with another powerful state or empire. The Roman Empire’s eastern border was shared first with the Parthian and then Sassanian empires.

Empires like Rome and the Han dynasty in China were also economic networks through which goods and resources could be exchanged. Peripheral areas were integrated into the empire because they provided some benefit to the center’s economy, typically resources or labor. The people who lived on the other side of the border were a part of this network of exchange as well. Imperial merchants often crossed the border to trade with neighboring peoples, even when this was forbidden! These merchants didn’t just trade goods, they also brought imperial culture and ideas with them. The barbarian groups closest to the empire almost always came to adopt, at least partially, characteristics of the empire (those in the empire didn’t usually want to admit this!).

Why do empires collapse?

Historians have long looked for exact causes behind the collapse of specific empires. Being historians, they disagree a lot, leading to a wide range of fallen-empire theories that are sometimes contradictory. So rather than spend a lot of time looking for that one, single cause of a collapse (barbarians! a lousy emperor! plague!), let’s try to understand some patterns within empires that make them vulnerable to collapse in the first place. There are two general measures that help us to evaluate the health of empires.

The first is money. Empires were really expensive, and as time went on in any empire, the expenses would go way up (armies, food and resources, education, propaganda, etc.). Eventually, there would be a financial breaking point where the usual problems that arise in such a complex system are too expensive to deal with. Some event will occur and the empire would collapse. How important is that event? If a delicate house of cards collapses because a fly landed on it, is it really the fly’s fault?

Healthy empires with adequate resources could respond to invasion, natural disasters, and even temporary shortages of money. However, over time each problem would become an increased burden on the empire and eventually, something would happen that the empire could no longer overcome. That “something” could be anything, but we have to see it as the proverbial straw that broke the camel’s back (remember Alphonse?).

The second measure is cohesion. As an empire aged over time, people in the center lost their sense of cohesion (unity) with the empire. Elites became more interested in their own wealth and local reputation than with the empire. Peripheral people and even groups located just beyond the borders of the empire developed a stronger sense of group identity, separate from those within the empire’s borders. As the emperor became increasingly unable to rely upon elites for help and taxes, the peripheral and border groups became more cohesive. New groups rose up on the edges while the center lost its power.

These two factors of cost and cohesion fed off each other in a way that sped up the empire’s collapse. As the empire struggled to meet growing expenses, the elites in the center were less motivated to help the emperor maintain control. When a crisis hit—such as rebellion, plague, or attack from outside groups—the emperor was eventually unable to respond and the empire itself would begin to collapse.

Connected to cost and cohesion is the inconsistent number of people in the empire. The growth, decline, or reorganization of populations could dramatically affect the course of an empire. If the tax-paying population decreased too much, or if peasants moved out of reach of the tax collectors, the empire would suffer from lack of funds. A population that grew too much put pressure on available resources. And that’s no fun because when an empire couldn’t provide what its people needed, they usually rebelled. Peasant uprisings could bring down empires just as fast as invading armies or plagues.

From theory to reality: Han dynasty China and the Roman Empire

In this lesson, we will learn mainly about the fall of the Western Roman Empire in 476 CE and the fall of the Han Dynasty in 220 CE. The Romans and Han were powerful and successful empires that left deep impressions on their respective regions. Both experienced similar problems that helped bring about their end, and those problems are related to the two measures we described above. A closer look at those issues is a great way to understand the general life cycle of an empire.

First, let’s look at the money measure. Both Rome and the Han dynasty suffered financial loss as elites began to pocket taxes for their own use. Then the empires lost even more tax revenues due to a loss of population because fewer people meant less taxes could be collected. In Rome, it wasn’t that the numbers changed so much as the distribution. Peasants relocated for the specific purpose of living outside the reach of tax collectors, and tax revenues had plunged 50 percent by the year 431 CE. Similarly, parts of China ruled by the Han dynasty became depopulated as people sought safety from increased barbarian raids along the borders. It was kind of a downward spiral because the tax collectors could not reach the people who fled, and they needed that tax money to keep fighting off the barbarians that scared them off in the first place.

Both empires also had problems with cohesion. The Romans and Han were so confident in their imperial superiority, they tended to marginalize and mistreat these outside groups and some conquered people. Bad idea! Once the different groups realized how strong they would be by coming together, they became a much more serious threat to the nearest empire.

There is another specific issue that these two empires shared. Both the Romans and Han dynasty rulers of China also had a habit of sometimes putting a child in the emperor seat, valuing lineage over experience. Whether or not they were nice kids, they usually weren’t able to deal with the growing list of problems. Neither empire could survive all these complications—the Western Roman Empire disappeared while the Han dynasty broke up as the peripheries became separate kingdoms.

Collapse elsewhere

Examples of imperial collapse can also be seen in other great states, and in other time periods. One is the Persian Empire. From 334-323 BCE, Alexander the Great conquered the Persian Empire. He was an impressive warrior, but the empire he conquered had been greatly weakened by internal issues, making it especially vulnerable to Alexander’s invasion. To briefly summarize what was going on before Alexander arrived: there was a civil war as brothers fought over the throne (404 BCE), the cruel rule of Artaxerxes III (358-338 BCE), and the assassinations of Artaxerxes III (338 BCE) and his young son Artaxerxes IV (336 BCE). The final ruler, Darius III, tried to hold together his weakened empire. But then the formidable Alexander showed up like a well-rested boxer facing an empire that had already gone 11 rounds.

Europe and Asia do not have a monopoly on imperial collapse; just consider the Andes zone of South America. The last Inca emperor, Atahualpa, was executed by the Spanish in 1533 CE, effectively ending the vast Inca Empire that had ruled over much of western South America. This story has usually been told as the victory of superior Europeans over primitive Inca, but that is not entirely accurate. The Inca had created a sophisticated empire that in many ways was far more complex than the Spanish Empire was at that time. But the Spanish had pretty lucky timing, arriving right when the Inca were emerging from an eight-year civil war. Inca elites had become less interested in helping the emperor, and peripheral groups had been forming stronger, anti-Incan identities. (Are these patterns starting to sound familiar?) The Spanish used these discontented groups against Atahualpa, and it worked. Rather than defeat the Inca with their small army, the Spanish took advantage of Inca weakness and used its peripheral peoples against it.

Now let’s move north to Mesoamerica. Historians have argued that the Maya Classical Period (250-900 CE) collapsed due to deforestation linked to overpopulation. As the population grew, more forests were cut down to create fields. At the same time, the climate shifted, causing a long period of drought. This caused a couple of big problems, as farming became less productive and rulers had to change their trade patterns. This weakened the position of rulers and led to rapid collapse. Recently, however, this version of events has begun to change. Archaeologists have determined that while the population did grow quite large, Maya farmers took conservation needs into account as they changed the landscape. In fact, this large population survived two major periods of drought without showing any signs of collapse. So it’s not like another drought was going to take them by surprise. While population growth and deforestation may have played a role in the eventual collapse of the Maya, they were not the key causes.