To a nomad, first encountering an ancient city must have been much like walking into one of our science fiction movies, only more incredible. After all, we have cities on which to base our concepts of science fiction movies. The nomad really had little or nothing to give him the idea for our ancient city. One should see what a remarkable leap forward it was when the human animal started changing the face of the earth with cities. If agriculture, with its surplus that frees other people for other pursuits, is the backbone of civilization, cities are its heart and soul. Cities are where those extra people congregate to practice the arts and skills of civilization: pottery, metallurgy, weaving, art, architecture, literature, commerce, and so on. Even the word civilization shows the importance of cities to it, since it comes from the Latin word, civitas, meaning city.
The earliest cities arose around 8000 B.C.E., soon after the birth of agriculture, although they do not always seem to have been dependent on farming to survive. The oldest know city was Jericho, dating back to c.8000 B.C.E., making it twice as old as the Egyptian pyramids. Jericho was a desert city, located around a fresh water spring and largely owing its existence to that spring, since traveling caravans would trade their goods to the people of Jericho for its water. Jericho probably had several thousand inhabitants, who were well enough organized to build a fairly impressive city wall, citadel, and reservoir and dig a moat out of solid rock. Another early city, Catal Huyuk, in modern Turkey, dates from about 6500 B.C.E. It was a religious center, living off of a combination of hunting, farming, and trade.
Isolated cities such as Jericho and Catal Huyuk did not create civilizations. That accomplishment depends on a number of cities spread out over an area and sharing a common culture: language, technology, religion, art, and architecture. The first civilizations arose along hot dry river valleys in Egypt, Mesopotamia, northwest India, and China. The importance of rivers to these civilizations has given rise to the term : hydraulic civilization, coming from hydra, the Greek word for water. Such rivers provided easy transportation and trade for people in their valleys. Such people traded goods and also ideas. In time, a common culture would emerge, as each village would tend to adopt the better ideas and techniques of its neighbors along the river. The rivers and the hot dry climate spawned another activity critical to early civilizations: irrigation.
Let us focus on Mesopotamia, where the Tigris and Euphrates rivers were the only reliable sources of water for farming. The fact that these rivers flooded annually gave the farmers the idea of bringing river water to their fields. At first, it involved nothing more than catching floodwaters and letting them gradually run back to the fields. In time, as the population and need for more farmland increased, the irrigation got more involved and complex. Such a project required a high degree of organization and cooperation, and that required leadership. Keep in mind, ancient peoples viewed rivers as gods. This meant that cutting into them and tapping their water supplies had religious implications. As a result, the local village priest supervised the irrigation.
In return, the priest would get offerings of grain and farm animals. Since these offerings were much more than he could consume himself, the surplus food served as the earliest form of "capital", that is wealth that can be invested in operations beyond what is needed for survival. Naturally, the priest put the "capital" back into his "business", building a bigger temple and storehouse to hold the extra grain and animals. This involved hiring extra accountants, builders, and guards who would settle with their families around the temple. Over time, the irrigation would lead to more crops, which led to more people, which led to the need to develop more farmland and irrigation. This, in turn led to more offerings and further expansions of the temple and the settlement around it. Once the town was large enough, craftsmen would move in who would provide needed goods such as pottery and tools to the temple's workers. Thus, a third level of population below those of the priest and their workers would emerge. Over the centuries, as the population, irrigation, and temple kept expanding, what was once a small farming village evolved into a thriving city gathered around the temple. Such a city would need or want wood, limestone, metal, and other goods that the area could not supply. As a result, some men would become merchants, traveling far and wide to trade the city's surplus for other goods. In this way, the city would grow even more populous and wealthy.
The long, continuous river valley of Mesopotamia meant that not just one village priest, but dozens were faced with the problems and rewards of irrigation. Thus, the process of cities growing up around temples was repeated over and over throughout Mesopotamia. Since the rivers tended to create a common culture, these cities resembled each other quite a bit in how they grew up and even in how they looked. For example, temple expansion generally took the form of building additions on top of the older temple. This gave the temples, or ziggurats as they were called, the appearance of pyramids. At this point, with dozens of cities united by a common culture springing up throughout Mesopotamia, we can say civilization has emerged. Its first people, the Sumerians, step onto the stage of history around 3000 B.C.E.
Civilization brought problems as well as blessings. For one thing, the continued expansion of population and farmland to feed it eventually led to cities clashing over new lands. With civilization came the first wars. Since priests were ill suited for fighting, they would choose a lugal, ("great man") to lead them in the fight. After the war, the lugal would be expected to resign his office. However, either because of ambition or the fact that another war was always around the corner, the lugal would keep his office. In time, he became a permanent official, the king, who led the city-state in war and administered justice in peacetime.
This often led to tension with priests who felt their own positions threatened. The temple (or, more technically, the gods) controlled most of the land. This often made the temple unpopular with the people, who looked to the king for protection. Eventually, the king would emerge as the most powerful figure in the city, although the temple would remain quite influential, still controlling much land, patronizing the arts, and acting as a grain bank and redistribution center during times of famine.
Another problem brought on by civilization was that the larger population of cities (sometimes 20-30,000) meant that people did not always know one another. This led to distrust and oftentimes crime. The influx of wealth also meant more clearly defined social classes since the wealth was not distributed evenly. This, plus all the different types of jobs being done, led to distrust and disagreement. Law codes had to be formed and courts of justice maintained, which also led to the need for a king's strong central government.
Cities and civilization also gave rise to new arts, crafts, and technology. Weaving was certainly one of the most remarkable crafts if we consider how much imagination it took to see a fabric in the fiber of the flax plant. Its importance should be obvious to anyone who wears clothes. Pottery was another craft of great significance. Sealed pottery jars could keep bugs and vermin out of peoples' food supply, preserving it in terms of quantity and hygiene. The rise of civilization also saw the evolution of two other types of technology vital to our way of life: writing and metallurgy.