Your community and networks have probably changed over time. As a baby, maybe it was just your parents or siblings. Then you go to school and meet other kids. But as you grew up, your network grew to include people farther away. Maybe you met some through social media, from listening to the same music or playing the same games. Your sense of community also grew over time as you made friends who lived in other parts of town or even other cities or countries. But networks and communities don’t always expand. Sometimes, they can shrink. Think about if you ever had to move or lost interest in a game.

We can see these same simple patterns throughout human history. Our foraging ancestors lived in communities of fewer than 250 people, moving around in search of food. Experts believe suggests 250 people is about as large a group can get without laws or writing. These family-based groups met and traded with their neighbors. While networks grew through trade, community sizes stayed the same. The growth of cities and states changed all those things. For the first time, people were living in communities of thousands and under the control of a government. The government set laws and made rules about how people should act. Cities and states both supported trade, first in very local networks and then along much longer distances.

In this unit, we look at how very large states—called empires—and belief systems (also known as religions) began to develop and spread. Both empires and portable belief systems represented another scale of growth for communities. Let’s talk about how and why that happened. But first, understand that the growth of communities and networks didn’t happen for everyone at the same time or at the same rate. And sometimes, even if just temporarily, they shrank. Still, this period did experience growth, so let’s discuss how that expansion happened.

The development of portable belief systems

A portable belief system is one that can be adopted by anyone, anywhere. Another term for portable belief systems you may be familiar with is religion.

Today, our world contains vast communities of people who belong to the same religion. Some of the largest religions are Hinduism, Buddhism, Christianity, Judaism and Islam. While some belief systems are very local, others have spread all over the world and have millions of followers. Within communities, there may be disagreements and differences. But followers are still bound together by a set of common beliefs and practices.

Early belief systems in this era were mostly tied to a specific place or group. People associated their gods with rivers and mountains. Or they visited shrines or temples to speak to gods. But about 3,000 years ago, some people began to think of their gods as universal. That meant they could communicate with their gods no matter where they were. Anybody, regardless of location, could belong to their religious community. These beliefs in universal gods allowed people to create vast networks based on religion. So people who traveled away from home could find others that shared their beliefs to do business together, find a place to stay, or worship together. There were huge advantages to joining these portable religions, and many people did so—although, of course, some did not!

But it’s important to note that as religions grew, people changed them to fit their way of life. Sometimes people even mixed the new religion with their local beliefs. As we’ll see in this unit, the expansion of religions meant a lot of mixing and matching. This process is called syncretism. It’s worth learning about this kind of blending and changing because it happens so often in human history, and not just with religion.

The growth of empires

As religions grew, so did the state. States are political units that share a single ruler (or system of rulers) and a common set of laws, borders, and government. States also grow, often by conquering new groups of people who have different laws and governments. And as states expanded, they had to figure out how to get conquered people to follow their rules and government. One solution to this problem was the empire.

Empires are more than just large states. Empires rule societies that contain many different communities. These people live in different cities and regions with many religions, ethnicities, and languages. Generally, the empire's solution isn’t to make everyone equal. Rather, in an empire, one group of people holds significant power over other groups, who are treated poorly.

The first empire was established in Mesopotamia around 2400 BCE by Sargon of Akkad. That’s almost 4,500 years ago. There have been many different empires since then. Often, the rulers of an empire let their subjects carry on their own customs and practices, but conquered people had to pay tribute or taxes. In other cases, empires were very controlling and took advantage of the people they colonized to benefit their ruling class.

Empires were a useful solution to the problem of ruling over large communities of different people. In addition to Mesopotamia, there were other vast empires. There was the Persian Empire, the Zhou and Qin dynasties in China and the Mauryan and Gupta empires in South Asia. There was also the Macedonian Empire ruled by Alexander the Great.

Two of the great empires of the ancient Afro-Eurasian world were the Roman Empire and Han Dynasty China. Afro-Eurasia refers to Europe, Africa and Asia. These empires had to come up with many new ideas to rule over great distances. They invented complicated road systems for better trade networks. They also had bureaucracies, which are governments made up of many officials and departments. These inventions helped both empires last for a long time.

The Roman Empire and the Han Dynasty existed around the same time. They helped create trade networks from Britain to China and Japan. However, they were different in many ways, including how they viewed the role of women in their societies.

Conclusion

Eventually, both empires collapsed. Empires often became politically unstable. This may happen when the populations who are not treated as well start to rebel. The Roman Empire and Han Dynasty China survived as long as they did because they developed new systems to hold everything together. But just as sometimes happens with people's personal communities, communities created by empires sometimes shrink. That’s a theme we will explore in the next unit, where we look at the changes that followed the fall of the great world empires.