Introduction In earlier centuries, through much of the 20th, it was not uncommon for individual cities to retain their position in the global urban hierarchy for many years. The prominence of Italian city-states lasted from the 15th through the 18th centuries. London, Paris, Madrid, and Amsterdam, among other cities, retained their positions at the top of the hierarchy for several centuries, in most cases until today. However, this was a period of relatively slow change in important elements such as technologies of transportation and of production, and power relations within nations tended to be rather stable, with intermittent interruptions from rebellions and short-term revolutions. Europe and the rest of the world had linkages but they tended to be confi ned to trade and occasional intellectual transfers. The integrity of most of the nations remained unaffected by contact with others that might present a fundamental challenge; the obvious exception being the intrusions of European and other colonial powers into Africa, the Americas, and Asia, but even here, if not enslaved, much of the colonial society remained unaffected with a power elite making most of the accommodation.