In order to understand how urban disaster risk changes, it is essential to understand how cities change. This chapter argues that cities are continually evolving entities whose past and present dynamics provide insights into future trends and possibilities. The chapter first reviews global trends in disaster losses, along with well-established definitions and frameworks about disaster risk. It explains why these are inadequate for understanding how a city’s disaster risk changes over time. It then proposes a simple conceptual framework, the Urban Risk Dynamics framework, to help guide empirical study of evolving disaster risk in any city. The framework is based on several premises: that local geography, or landscape, is vital to understanding urban disaster risk; that cities must be understood as economic entities; and that technological change is a key driver of urban change. The chapter then introduces and justifies the selection of the six case studies to be analyzed using the framework in Chapters 3–5.