How did cities first develop?
Cities developed from agricultural villages that grew around key resources — particularly irrigated river valleys. In Mesopotamia, temple complexes became organizational centers managing labor and grain, attracting specialists and traders. By 4000 BCE, Uruk had grown into the world's first true city with tens of thousands of inhabitants.
The development of the first cities was a gradual process driven by agricultural surplus, organizational complexity, and the gravitational pull of economic and religious institutions. It happened first in southern Mesopotamia, where the challenges and opportunities of irrigated agriculture in the Tigris-Euphrates floodplain created the conditions for urbanization.
The process began with successful farming villages that produced more food than they consumed. This surplus attracted non-farming specialists — craftspeople, traders, priests — who provided goods and services in exchange for food. Temple complexes emerged as organizational centers, managing communal grain stores, coordinating irrigation maintenance, and mediating between the community and the gods.
As these temple-centered communities grew, they developed new forms of organization. Writing was invented to track increasingly complex economic transactions. Specialized administration emerged to manage labor, resolve disputes, and coordinate large-scale projects. Social hierarchies crystallized as certain families accumulated wealth and authority.
By around 4000 BCE, the Sumerian city of Uruk had grown to perhaps 40,000 inhabitants — vastly larger than any previous human settlement. It had monumental temples, diverse neighborhoods, craft workshops, and a class of professional scribes and administrators. It was a city in every meaningful sense: a dense, complex, diverse community organized around institutions that served a wide region.
The urban model spread — sometimes through direct influence, sometimes through independent invention. Cities appeared in Egypt, the Indus Valley, China, and Mesoamerica, each reflecting local conditions and cultural values, but all sharing the fundamental characteristics of density, specialization, and institutional complexity.