Long-distance interaction predates cities, but the scale, intensity, and organizational complexity of exchange during the Urban Revolution were unprecedented. How did early urban societies sustain transcontinental trade without modern transport technologies, financial instruments, or formal institutional infrastructure? We address this question through a formal network analysis of the Uruk Expansion in Chalcolithic Mesopotamia (ca. 4000–3000 BCE), widely regarded as the earliest episode of globalization. Drawing on a newly assembled dataset of more than 1,700 settlements and documented interaction routes, we reconstruct evolving patterns of connectivity across Mesopotamia and its peripheries. Our results show that exchange networks initially structured around riverine corridors gradually transformed through processes of diaspora settlement and intermediary bridging. These dynamics generated increasingly dense clusters and, over time, small-world network properties that balanced strong local integration with efficient long-distance connectivity. This transition from sparse, branching systems to grid-like integrated networks challenges core–periphery and dependency-based interpretations, instead highlighting an emergent process of market formation and self-organized coordination in early urban economies.

First Author: Giacomo Benati

Co-Authors: Sergi Lozano

Keywords:
network analysis
urban revolution
early markets