Our world is organized in nation-states, roughly 190 as of this writing. Almost every nation-state is represented through a capital, and most capitals are cities. These cities are embedded in diverse indigenous settings, display very different physical shapes, and have distinct domestic and international reputations. Nuku'alofa (population 22,000), capital of the South Pacific archipelago of Tonga, and Cairo (population 8.1 million) belong to this group of cities, as do Berlin and Washington, D.C., which represent, respectively, one of Europe's largest nation-states and the world's only remaining superpower.

What makes a city a capital? All capitals share the fact that they are privileged vis-à-vis other cities within the same political system. They represent the larger political entities surrounding them; since the early modern epoch, these entities have become successively nations and nation-states. Capitals are expected to perform specific functions for their nation-states. These functions allow a capital to act as a “multiple hinge”: a capital mediates between its urban space, the surrounding society, and the nation no less than between the nation-state and the international world. Often, capitals also have a distinct social life and display a particular cultural dynamic that goes beyond predefined functions.

The essays in this volume deal with both the hinge role of capitals and their distinct dynamics by focusing on the relation between capital cities and nation-states. Berlin and Washington provide the empirical focus: two capitals that have long been disputed and reveal paradigmatically the plurality of capital meanings from the late eighteenth century to the present. The contributors to this volume explore the cultural and political roles that Berlin and Washington have performed through their urban shape and architecture, their social life and metaphorical meaning, and through the ideas that city planners, politicians, and visitors from abroad have formulated to define the character of these cities. In particular, the chapters address the question whether and how these two capital cities have served to articulate a national identity. The volume thus aims to provide new insights into the relationship between urban spaces, nation-states, and political ideas in the modern era.