There’s no law that says that people must live in states. There’s nothing that says states must be divided into cities. And there’s neither an ironclad reason that people living in states and cities must be farmers nor that they have to trade with people living in other agrarian (farming-based) states and cities. But these four things tend to go together, and this unit is all about why and how they fit with each other.

Now, there are many reasons why the history we read about and study tends to focus on agrarian cities and states. For example, history tends to be written by people who live in cities and states that are centers of farming and trade. Also, those cities and states tend to be places where ideas are exchanged and people come together in innovation and creative work, so they usually seem like important historical centers.

Still, a lot happened during the period we’re covering in Unit 3—and long after—within societies that weren’t states or cities, didn’t farm, and weren’t centers of trade. We’re going to be studying some of these societies as well, but the rate of change in these types of societies was generally slower, so we will be putting more attention on the development of trade, the growth of cities, and the emergence of states—three changes that transformed the way humans live, connect to each other, and make stuff.

Village networks

Let’s start with trade. By 6000 BCE, our ancestors had already spread from Africa to most of the world’s continents and large islands. Some of these people were farming and herding animals; many continued to forage for wild plants and animals. In both cases, these societies adapted and created new strategies and tools suited to their local environments.

Innovation and adaptation were often driven by environmental change, but just as often, they were the result of exchange between societies. New techniques, strategies, ideas, and tools were often invented in one place, and then shared with other societies through trade, warfare, and intermarriage. As societies met, they frequently copied their neighbors or adapted the new ideas to serve their own needs. Some of the most important inventions in human history—like iron tools—were only invented once or twice independently, and then spread through networks, around the world as different communities met, traded with, and fought each other.

In this period, the most important networks for everyday life remained local. Agricultural villages connected to each other and to nomadic communities. These sorts of networks connected pastoralists, farmers, and foragers, allowing each group to specialize in a few products. They could then trade these products with their neighbors who produced different goods. To understand these networks, we will spend some time looking at different types of communities and the ways they were linked together in circuits of exchange and interaction.

Long-distance trade

Trade networks started out local, but they didn’t stay that way. In every world region, long-distance trade networks moved goods, people, and ideas. As cities emerged, a new type of network developed: the metropolitan network. These networks connected cities with the villages and rural areas around them, which they could control to some degree because of their larger population.

Then, even larger trade networks developed in many places. In Eurasia, the domestication of horses allowed for much speedier communication and helped rulers extend their influence and control over people hundreds of miles away from the capitals of their empires. Similarly, the domestication of the camel in western Asia and Africa meant that people and goods could now move across deserts at an accelerated rate. Llamas came to play a similar role in some parts of the Americas.

At sea, new and improved shipbuilding and navigation technologies helped trade extend across larger areas. In the Caribbean, the Mediterranean, and the Baltic seas—and later the Pacific Ocean—vast networks of exchange relied on the expertise of communities that specialized in shipbuilding and sailing (or rowing). On land, as well, technology began to make a difference. In many regions, infrastructure projects such as the building of roads connected people to each other in more-efficient ways.

As a result, more people traveled—although the number of people traveling compared to the overall population was still quite low. But for those that did travel, they learned each other’s languages, read each other’s ideas, and spread those ideas to new places.

Cities

Alongside long-distance trade routes there emerged another human innovation: the city. The relationship between trade and the city is kind of a “which-came-first-the-chicken-or-the-egg?” problem. To some degree, cities grew up around markets, where traders from different places were already meeting. But the growth of cities also stimulated trade, because some people in cities had excess wealth of some sort—coins, or food, or commodities—and they wanted to use that wealth to buy luxury goods that improved their lives.

Cities developed in different parts of the world at different times. The oldest cities probably emerged in Anatolia, Mesopotamia, and Egypt nearly 6,000 years ago, and in China, India, and Southeast Asia 5,000 years ago. Another wave of urbanization began 4,000 to 2,500 years ago in Mesoamerica, the Andes mountains of South America, the Mediterranean Basin, and sub-Saharan Africa.

Cities were built for different reasons: to take advantage of trade routes, for defense from enemies, for religious purposes, and as seats of government, for example. They were usually found in agrarian societies, because only farming provided enough surplus food to feed the soldiers, priests, builders, and other specialists that cities needed. But there was no single model of an agrarian society, nor was there one model for a city. Shang Dynasty China, Nubia, Chavín de Huántar, Aksum, Nok in West Africa, the Indus River Valley, Mesopotamia—each community imagined and implemented their own particular patterns of society.

One thing these societies did share—and foraging communities probably didn’t—was that each had a group of people who were quite wealthy. Usually, the wealthy were a small group, and most people in cities were, by comparison, poor. This poor majority worked hard and suffered from diseases due to the concentration of people, animals, and excrement that cities produced.

States

Long-distance trade played a role in concentrating immense amounts of wealth in the hands of a minority of people. These “elite” classes had privileges and power, thanks to their control of wealth. In order to protect those privileges, elites pioneered the development of the state—rules, laws, government structures, and military that protected people in a society, but especially the wealthy. In their pursuit of power and wealth, elites could drive states to undertake violence and war at scales never-before seen in human societies.

The rise of the state was closely connected to the development of writing—probably the most important development during this era. The ability to read and write was rare and generally something only the wealthy had. Therefore, writing deepened the distance between elites and commoners. The first written texts weren’t love poems or novels; they were inventories and receipts. Writing started as a way to record the trading of goods and surpluses of food. Writing allowed a merchant to record that they had traded three goats for five bushels of wheat. It let rulers write down instructions to the commanders and governors overseeing the furthest edges of their states.

Still, not all states were the same, as we will see. The hierarchical structure of Assyria, in Mesopotamia, was quite different from the negotiated power of Jenne-Jeno, in West Africa. The decentralized rule of religious leaders in the Olmec cities of Mesoamerica reveals big differences from the centralized power of Akkadian kings in Mesoamerica.

Despite all the connections that developed during this period, human societies remained quite diverse. In fact, the wide range of economies, social structures, and cultures in this period helps remind us of the shared creativity that is a human trait. There’s no single pathway for human societies. Each is a product of trade and exchange mixed with local ideas and the genius of individuals. Ancient societies unleashed that genius in ways that made for unique communities while contributing to a shared human history.