• An empire consists of a central state that also controls large amounts of territory and often diverse populations
  • Empires rise and grow as they expand power and influence, and can fall if they lose control of too much territory or are overthrown
  • Historians can better understand these processes by comparing how they occurred in different empires

What is an empire?

By now, you have learned about several major empires. Just to review, the term empire refers to a central state that exercises political control over a large amount of territory containing many diverse groups. Often, this centralized power rules from one or several capital cities. We usually refer to an empire as if it were a single unit. But, because empires are so large, they are often divided into smaller, more manageable political units, usually called provinces.

Comparing how empires rise and grow

For an empire to grow, one state has to take control of other states or groups of people. To better understand these processes, historians can compare specific empires against one another.
By comparing different empires, historians see that the process of growth had some similarities and some differences across empires. The Achaemenid Persian Empire under Cyrus the Great grew substantially in less than 30 years and reached its greatest extent within 75 years. The Roman Republic was founded in the sixth century BCE, but the Roman Empire didn’t reach its greatest extent until 117 CE.
Empires grow for different reasons. The Persian Empire of the Achaemenids was built largely through military conquest. The Maurya Empire in India used a combination of political sabotage, religious conversion, and military conquest to expand its rule. The Romans, although a militaristic society, did not generally set out to conquer territory. But, they did get involved in many wars. After defeating enemies, Rome usually offered them some level of citizenship in exchange for loyalty.
The main point is that imperial growth is about a central state extending political control over territory and people. This can be achieved by military, economic, or cultural means—usually a combination of these factors!
Stop and consider: What have historians found by comparing the process by which different empires have risen?
Choose 1 answer:
Choose 1 answer:
There were important differences in how empires rose to power, but the core idea of a central state expanding its power is the same in all cases.

Rapid expansion—the rise of Alexander the Great

Alexander of Macedon is remembered as one of the great empire builders of history. But how much of his success was due to his personal qualities? The rapid rise of Alexander’s empire was an example of the process by which a small state can grow into a huge empire. It also demonstrated how events and circumstances beyond the central state play a role in the state’s success in building an empire.
Although he is often remembered for being the father of Alexander the Great, Philip II of Macedon—who reigned from 359 BCE to 336 BCE—was an accomplished king and military commander in his own right. He set the stage for his Alexander’s victories over Persia. Philip II used bribery, warfare, and threats to secure his kingdom, and without his insight and determination, history might never have heard of Alexander.
Map showing the expansion of Macedon.
Map showing the expansion of Macedon. Image credit: Wikipedia
In 336 BCE, after Philip was killed, Alexander embarked on the great campaign his father had been planning: the conquest of the mighty Persian Empire. Alexander had impressive military leadership abilities, but he was also aided by political instability in Persia. Alexander's victories convinced many local rulers to swap Persian imperial control for Alexander's rule. Alexander did not drastically challenge existing administrative systems, rather, he adapted them for his purposes. By 327 BCE, the Persian Empire was firmly under his control.
Alexander’s conquest of Persia can be viewed as a change in leadership, as well as an act of territorial expansion. The territory that constituted the Persian Empire remained largely intact under Alexander’s rule. Several factors, including the existing conditions in the Persian Empire and the imperial foundations laid by his father, combined with Alexander’s military skill to make his imperial adventure successful.
Stop and consider: Could Alexander have been successful in Persia if his father, Philip II had not first conquered Greece?
Reasons for saying no
It seems likely that Alexander would have learned a lot of military operations from Philip II. So, Alexander would probably not have been as good a general if Philip II had not participated in so many military campaigns.
Philip II's conquest of Greece provided Alexander with wealth and resources. By uniting most of Greece under his rule, Philip II built a well of financial and political support for Alexander's later invasion of Persia. Without the resources and the men to fight in his army, Alexander probably could not have invaded Persia.
Reasons for saying yes
Alexander used a strategy of leaving local leaders in charge, as long as they switch their allegiance to him. This meant he could draw on the resources of his new conquests more quickly and easily. This strategy might have been successful even if Alexander did not have Philip's previous conquests to build on.

Internal reform—the rise of Han China

The Qin dynasty was short-lived—from 221 BCE to 206 BCE. But during its brief existence, it laid the groundwork for an extensive imperial bureaucracy that would expand and reform under the Han Dynasty that followed it. Qin Shi Huang, the first Emperor of the Qin, consolidated land and power during his conquests that ended the Warring States Period. Under Qin Shi Huang, all power came directly from the Emperor.
The first Emperor of the Han, Han Gaozu, retained much of the Qin imperial bureaucracy but reduced the harshness of edicts and taxes. Confucianism had been suppressed by the Qin. Han Gaozu openly promoted Confucianism as the state ideology, encouraging moral uprightness and virtue, rather than governing solely through fear and oppression.
Further, the Han leaders pressed a policy of cultural conversion on newly-conquered regions. Through efforts to teach Confucian ethics, the Han emperors built a shared sense of identity among their diverse subjects. Allegiance to the central Han state became more than a political or economic relationship—it was part of a cultural identity.
Stop and consider: How did the Han approach of forced cultural conversion compare with the strategy used by Alexander to gain loyalty from new subjects?
The Han Dynasty actively tried to make people embrace Confucian thinking. The goal was to get people to support the empire by imposing shared cultural beliefs and practices. The reasoning behind this strategy was that shared beliefs would create a stronger sense of Chinese identity and increase loyalty to the central government.
Alexander tried to win over newly-conquered people by leaving cultural and political institutions intact. The goal was to make sure people were loyal to their new leader, Alexander, by showing them he was not going to interfere in their daily activities. Unlike the Han, Alexander reasoned that letting people maintain their own cultural practices would prevent them from disliking him as a ruler.
This comparison shows us that different strategies for imperial control could work under different circumstances! The Han Chinese wanted to consolidate their control over a set amount of territory. Alexander wanted to keep his army moving, he chose not to try to change the cultural habits of his new subjects.

Comparing how empires fall

When historians say that an empire fell, they mean that the central state no longer exercised its broad power. This happened either because the state itself ceased to exist or because the state’s power was reduced as parts of the empire became independent of its control. Because empires are large and complex, when historians talk about the fall of an empire, they are typically talking about a long process rather than a single cause!
Some of the broad factors that historians use to help explain imperial collapse are:
  • Economic issues
  • Social and cultural issues
  • Environmental issues
  • Political issues
These are not causes by themselves, but ways to categorize causes. For example, you wouldn’t say, “Politics are one reason Rome fell.” You would look at specific political factors, such as the impact of civil wars. Although these categories of factors are necessary if we want to talk about imperial collapse, there is not a single explanation for why empires fall!

Rapid collapse—Achaemenid Persia

Although there had been internal conflicts in Achaemenid Persia prior to Alexander’s invasion, the empire remained largely intact for much of the fifth and fourth centuries BCE. However, the existence of internal divisions made Persia vulnerable to invaders hoping to strip Persia of territory.
In 334 BCE, Alexander of Macedon invaded the Persian Empire, and by 330 BCE, the Persian king, Darius III, was dead—murdered by one of his generals. Alexander claimed the Persian throne and left the officials and institutions of the cities he captured in place to manage his massive empire. In this sense, Alexander could be viewed as simply stepping into the role of Persian emperor. Rather than destroying the central Persian state, Alexander took over as its new ruler.
When Alexander died without an heir in 323 BCE, his generals divided the empire among themselves. It was at this point that the central state of Persia collapsed and was replaced by multiple competing states. This division occurred within a matter of years.
So, the factors that contributed to the fall of Achaemenid Persia were largely political and military. Political divisions made the empire weaker militarily.
A map of the division of Alexander’s empire among his generals.
Division of Alexander’s empire among his generals. Image credit: Wikimedia
Stop and consider: Which of the following pieces of evidence could support the claim that the Persian Empire didn't fall until Alexander's death?
Choose 1 answer:
Choose 1 answer:
Alexander didn't do much to change the structure of the Persian empire, either at the local or the imperial level. He even took Persian titles for himself!

Slow death of an empire—the Guptas

The Gupta dynasty ruled a large empire in northern India from roughly 320 CE to 550 CE. This dynasty reached the height of its power in about 450 CE, as shown on the map below. From about 450 CE on, the Gupta empire faced invasions in the northwest region of the empire from the Hephthalites—sometimes called the White Huns. These ongoing attacks drained Gupta military and financial resources and led to century-long process of decline.
This map illustrates nicely the idea of a core or central state exercising control over surrounding territories; notice that the core state is smaller than the actual empire it controls!
This map illustrates nicely the idea of a core or central state exercising control over surrounding territories; notice that the core state is smaller than the actual empire it controls! Image credit: Wikimedia, Woudloper, CC BY-SA 4.0
Continued conflict with the White Huns saw the Gupta Empire lose much of its northwest territory by about 500 CE. The Gupta Empire was able to force the Huns out in 528 CE. However, the economic impact of the loss of territory and continued fighting left the Gupta dynasty weak and poor. Over the next several decades, various regions broke away from Gupta control, and neighboring states—like the Vakataka Kingdom and Malwa—grew more powerful.
By 550 CE, the Gupta empire no longer existed. However, a small Gupta kingdom continued to exist for another century or so. The Gupta Empire is an example of imperial collapse where the central state continues to exist, but is unable to exert its power and influence beyond a limited territory. This can be contrasted with the Western Roman Empire, whose last emperor was forced out of power, eliminating the central Roman state.
The factors that contributed to the fall of the Gupta Empire were largely military and economic. The economic issues were a result of the military challenges the empire faced. This is turn led to political issues as the government lost territory and was weakened.
Stop and consider: How did the collapse of the Gupta Empire compare to the collapse of the Achaemenid Persian Empire?
The Gupta empire lost control of much of its territory. However, the Gupta dynasty continued to rule a small kingdom after its empire fell.
Achaemenid Persia
The Achaemenid dynasty was wiped out and replaced by Alexander the Great. The central Achaemenid state around which the empire was built no longer existed.

Big takeaways

  • Empires rise and fall for many different reasons
  • Historians often categorize these reasons as political, economic, social and cultural, or environmental
  • Comparing the specific causes and effects of the rise and fall of different empires can help us better understand the concept of empires across different times and locations
Article by Steven Schroeder.
"Alexander the Great." Ancient History Encyclopedia, 2013.
Freeman, Charles. Egypt, Greece, and Rome: Civilizations of the Ancient Mediterranean. England: Oxford University Press, 2014, 313.
"Philip II of Macedon." Ancient History Encyclopedia, 2014.