The cities and urban areas of the Baltic Sea Region are the main engines of its development. The concentration of economic activity, corporate decision-making, labour, foreign direct investment, knowledge, and innovation to its metropolitan regions is substantial. As such, the demographic magnetism of larger cities is also considerable, while rural areas in general and peripheral areas in particular continue to be underexploited resources. Spatial polarisation is increasingly dividing cities and regions into "actors" and "reactors". Small and peripherally located settlements that lack the necessary levers to actively take part in the international division of labour are affected most. Moreover, many of the Baltic Sea Region countries are relatively small in economic terms and are thus often simply unable to compete on a par with the major European economies, let alone globally. As such then, the concentration of effort into the promotion of a select few urban centres seems rational. This volume makes a specific effort to deal comparatively with a wide range of issues pertaining to the structure of the urban system in the Baltic Sea Region, and to present a comprehensive picture of its recent development patterns. The similarities and differences between the countries of the region are analysed here in a comparative manner, while the relationships between urban and rural areas are also highlighted.