Conclusion

Over the fourth and third millennia BCE, the world’s social landscape changed in significant ways. In a few key locations, where giant rivers irrigated fertile lands, complex human cultures began to emerge. These areas experienced all the advantages and difficulties of expanding populations: occupational specialization; social hierarchy; rising standards of living; sophisticated systems of art and science; and centralized production and distribution of food, clothing, and other goods. Ceremonial sites and trading crossroads became cities that developed centralized religious and political systems. As scribes, priests, and rulers labored to keep complex societies together, social distinctions within the city (including the roles of men and women) and the differences between country folk and city dwellers sharpened.

Although river-basin cultures shared basic features, each one’s evolution followed a distinctive path. Where there was a single river—the Nile or the Indus—the agrarian hinterlands that fed cities lay along the banks of the waterway. In these areas cities were small; thus, the Egyptian and Harappan worlds enjoyed more political stability and less rivalry. In contrast, cities in the immense floodplain of the Tigris and Euphrates needed large hinterlands to sustain their populations. Because of their growing power and need for resources, Mesopotamian cities vied for preeminence, and their competition often became violent.

In most areas of the world, however, people still lived in simple, egalitarian societies based on hunting, gathering, and basic agriculture—as in the Americas and sub-Saharan Africa. In Anatolia, Europe, and parts of China, regional cultures emerged as agriculture advanced and populations grew—but not with the leaps and bounds and fast-paced momentum of the river-basin cultures. Some of them, as in the Aegean and Europe, forged warrior societies. Beyond these frontiers, farmers and nomads survived as they had for many centuries. Thriving trading networks connected many, but not all, of these regions to one another.

Changes in climate affected everyone and could slow or even reverse development. How—and whether—cultures adapted depended on local circumstances. As the next chapter will show, the human agents of change often came from the fringes of larger settlements and urban areas.

TRACING THE GLOBAL STORYLINE

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A timeline of early civilizations around the globe. The timeline shows various civilizations represented by diamonds and lines color coded by region of the world that situated between and around lines representing 4000, 3000, 2000, and 1000 B C E. In Southwest Asia and Egypt the earliest Sumerian cities appear in in Mesopotamia at 3500 B C E, the first dynasty emerges in Egypt at 3100 B C E, Old Kingdom Egypt sits at 2686 to 2181 B C E, and Sargon’s Akkadian territorial state in Mesopotamia existed around 2334 to 2200 B C E. In South Asia the first cities appear in Indus valley at 2500 B C E. In East Asia Yangshao culture thrives along Yellow River from 4000 to 3000 B C E and Longshan culture flourishes in Yellow River valley from 3000 to 2000 B C E. In Europe and the Mediterranean fortified villages appeared in the Aegean at 2500 B C E and Stonehenge was constructed around 2000 B C E. In the Americas Chicama Valley culture thrives on Pacific coast of South America at 3500 B C E and Tehuacán Valley culture in Mexico thrives at 3500 B C E. In Inner and Central Asia dense village life appears along many lakes and rivers at 3500 B C E and the spread of pastoralism begins at 3500 B C E.