Contending that the city-state was a significant cross-cultural regularity that developed among geographically and historically separated civilizations, fifteen prominent archaeologists and historians explore the emergence, structure, and function of city-states in Mesopotamia, Egypt, the Indus Valley, China, Greece, Okinawa, the Maya Lowlands, central Mexico, the coast of Peru, and the Andes. The contributors discuss area and population size, settlement patterns, economic organization, political systems, and duration.