This book is about trends in migration to, and from, African towns and cities, and the changing characteristics of migrants and migrancy. To some extent, therefore, it is also about changing urban population dynamics in sub-Saharan Africa as an outcome of these shifts and the nature of urban livelihoods which is a key driver of migration. The core of the book is based on empirical evidence from longitudinal research in Harare, Zimbabwe. In the 1980s, ordinary residents of Harare were probably the most economically and socially secure urban people in sub-Saharan Africa. By the mid- 2000s, they were among the least secure. Over the same period most ordinary urban people in sub-Saharan Africa had suffered significant falls in their living standards, leading to adaptations in their livelihoods and the nature of migration (Potts 1997; Beall et al. 1999). Harare's experience provides in microcosm an extreme example of these falls and adaptations which can be traced through the evidence from directly comparable surveys conducted in the 1980s, 1990s and 2000s.