Urban centres were features of all early civilizations (Bairoch 1988: 1–70). Contrary to a once fashionable belief, there is no evidence of a ‘civilization without cities’ (J. Wilson 1960), and this includes early civilizations in which, instead of cities, there were supposed to be ‘ceremonial centres’ inhabited only by a few priests, where people from the surrounding countryside assembled periodically for religious observances (J. Thompson 1954; Wheatley 1971). Nevertheless, the nature of their cities varied considerably.

Towns and cities were once defined as communities of non-food-producers with a minimum of 5,000 people or a population density of at least 386 people per square kilometre (Burgess 1926: 118), but such definitions have been abandoned. Some legally chartered ‘cities’ in medieval Europe had only a few thousand inhabitants, while ‘farming villages’ in Eastern Europe and Italy often had several times that number (Chisholm 1962: 60–61). In parts of China and Indonesia rural population densities have long exceeded 386 people per square kilometre (Cressey 1955: 15; Huntington 1956: 428). Finally, both in early civilizations and in other preindustrial societies, considerable numbers of farmers lived in urban centres. As recently as 1910, almost 10 percent of the population of Cairo consisted of full-time cultivators (Abu-Lughod 1969: 164). The key defining feature of an urban centre is that it performs specialized functions in relation to a broader hinterland (Trigger 1972).