When looking at the development of ancient civilizations in both Egypt and Mesopotamia, it is clear that rivers and deserts played a vital role. In many ways, it was the environment that led to the development of these two civilizations.
Both Egypt and Sumer utilized their rivers as a reliable source of water for irrigation. In addition to water, the Nile in Egypt and the Tigris and Euphrates in Mesopotamia provided valuable silt from the mountains upriver to fertilize farmland year after year. These rich growing conditions, which gave name to the so-called Fertile Crescent, gave both civilizations the opportunity to stratify society. A class of farmers was able to provide enough surplus food to support people who did not farm. This led to the rise of merchants, a priestly class, nobles, and artisans. Furthermore, enough grain was grown to export, giving both civilizations the ability to gain even more wealth. The complex societies that developed needed methods to keep track of information and to communicate efficiently. This is largely why both the Sumerians and the Egyptians developed some of the earliest forms of literacy.
In Egypt, most farming was confined to the Nile delta. This is where there was enough water and fertile soil to support farming. The land outside this region was a barren desert without the resources needed to support large populations. Therefore, most of the Egyptian population and cities were concentrated in a relatively small area. By 3000 BCE, this gave rise to a single political unit ruled by the Pharaohs. In Mesopotamia, the two rivers provided water and fertile soil over a larger geographical area. This partly explains why Sumerian culture was not unified under a single polity. Instead, multiple city-states ruled by priest-kings came to define Sumerian governments.
The power of rivers heavily influenced religion. Their power was personified in their gods. In Sumer, Enil, the god of storms, was the most powerful of deities. He could take the form of a mighty flood and was, therefore, the most feared and respected of Sumerian gods. Unpredictable flooding was a real fear as it could destroy whole harvests and riverside cities. The Egyptian god of the Nile and floods, Hapi, was also highly revered. However, because the Nile flooded more predictably than the Mesopotamian rivers, he was seen as a life-giving force. It was to Hapi that the Egyptians looked to for the necessary floods that replenished the soil of their farmlands.