How rivers gave life to the first cities in human history

By 3000 BC, the development of agriculture had led to the production of surplus food in certain areas, particularly in the valleys of the Nile in Egypt, the Tigris and Euphrates in Mesopotamia, and the Indus. The communities living in these regions were thus able to diversify their activities, introducing, for example, metalworking and construction. In this way, the first markets were born which, by bringing in wealth, formed the core of the first cities. 

Urban centers grew primarily on the banks of rivers, near fertile agricultural land and sources of building clay. Rivers were essential for bringing raw materials into the city: wood, precious stones, and metals. Trade also developed by land, particularly through the Levant and the Iranian Plateau, connecting the cities of the three regions, as indicated by the wide presence in Mesopotamia of carnelian beads and seals, the latter used to mark the documents that accompanied the goods. Many cities in Mesopotamia grew to become powerful city-states, some even transforming into the capitals of the first known empires.