Politically as well as culturally and environmentally, Mesopotamian and Egyptian civilizations differed sharply. For its first thousand years (3200–2350 B.C.E.), Mesopotamian civilization, located in the southern Tigris-Euphrates region known as Sumer, was organized in a dozen or more separate and independent city-states. Each city-state was ruled by a king, who claimed to represent the city’s patron deity and who controlled the affairs of the walled city and surrounding rural area. Quite remarkably, some 80 percent of the population of Sumer lived in one or another of these city-states, making Mesopotamia the most thoroughly urbanized society of ancient times. The chief reason for this massive urbanization, however, lay in the great flaw of this system, for frequent warfare among these Sumerian city-states caused people living in rural areas to flee to the walled cities for protection. With no overarching authority, rivalry over land and water often led to violent conflict.

These conflicts, together with environmental devastation, eventually left Sumerian cities vulnerable to outside forces, and after about 2350 B.C.E., stronger peoples from northern Mesopotamia conquered Sumer’s warring cities, bringing an end to the Sumerian phase of Mesopotamian civilization. First the Akkadians (2350–2000 B.C.E.) and later the Babylonians (1900–1500 B.C.E.) and the Assyrians (900–612 B.C.E.) created larger territorial states or bureaucratic empires that encompassed all or most of Mesopotamia. Periods of political unity now descended upon this First Civilization, but it was unity imposed from outside.

Egyptian civilization, by contrast, began its history around 3100 B.C.E., with the merger of several earlier states or chiefdoms into a unified territory that stretched some 1,000 miles along the Nile. For an amazing 3,000 years, Egypt maintained that unity and independence, though with occasional interruptions. A combination of wind patterns that made it easy to sail south along the Nile and a current flowing north facilitated communication, exchange, unity, and stability within the Nile Valley. Here was a record of political longevity and continuity that the Mesopotamians and many other ancient peoples could not replicate.

Cities in Egypt were less important than in Mesopotamia, although political capitals, market centers, and major burial sites gave Egypt an urban presence as well. Most people lived in agricultural villages along the river rather than in urban centers, perhaps because Egypt’s greater security made it less necessary for people to gather in fortified towns. The focus of the Egyptian state resided in the pharaoh, believed to be a god in human form. He alone ensured the daily rising of the sun and the annual flooding of the Nile. All of the country’s many officials served at his pleasure, and access to the afterlife lay in proximity to him and burial in or near his towering pyramids.

This image of the pharaoh and his role as an enduring symbol of Egyptian civilization persisted over the course of three millennia, but the realities of Egyptian political life did not always match the ideal, as the Portrait of Paneb so vividly illustrates. By 2400 B.C.E., the power of the pharaoh had diminished, as local officials and nobles, who had been awarded their own land and were able to pass their positions on to their sons, assumed greater authority. When changes in the weather resulted in the Nile’s repeated failure to flood properly around 2200 B.C.E., the authority of the pharaoh was severely discredited, and Egypt dissolved for several centuries into a series of local principalities.

Even when centralized rule was restored around 2000 B.C.E., the pharaohs never regained their old power and prestige. Kings were now warned that they too would have to account for their actions at the Day of Judgment. Nobles no longer sought to be buried near the pharaoh’s pyramid but instead created their own more modest tombs in their own areas. Osiris, the god of the dead, became increasingly prominent, and all worthy men, not only those who had been close to the pharaoh in life, could aspire to immortality in his realm.23