Urbanism in the Indian subcontinent occurred in three distinct time periods in which cultural cohesion over large regions is archaeologically demonstrated through the architecture and artifacts of social, ritual, and economic activity. In the Indus (2500–1900 B.C.) and Early Historic (3rd century B.C. to 4th century A.D.) periods, cities were not necessarily tied to political territories or guided by strong political leaders, but by the Medieval period (after the 9th century A.D.), urban zones were the base for political growth, warfare, and aggrandizement. The comparison of these three eras is undertaken within a framework for defining cities that balances quantitative criteria such as population size and areal extent with two types of qualitative criteria: internal specialization on the basis of materials found within archaeological sites, and external specialization on the basis of data recovered through regional analysis. Cities from the three eras also are evaluated from the perspective of the ordinary inhabitant through the examination of the social, religious, and economic factors that prompted and rewarded urban residence. While the Indus and Early Historic cities were attractive because of the networks of opportunity found there, Medieval cities additionally benefitted from a “push” factor as ordinary inhabitants allied themselves to urban areas in times of political stress and uncertainty.