The chapter proposes an overview of global urbanization since 1950, relying on the structural and dynamic principles of the evolutionary theory of urban systems and on the observations of some of the major financial linkages connecting
cities. We analyze first an overview of the state of urbanization at the world scale using statistics collected and provided for all 195 nation-states of the United Nations. We then examine the extent to which the income level and human development index of countries are correlated with the urbanization rates. Trajectories of cities underline the booming cities including many Asiatic and African cities opposed to the relative declining cities. The total weight of emerging metropolises mostly located in Southern countries passed the total population of the other groups of relatively declining cities between 1980 and 2010. It is highly critical for the urban future that the large majority of urban citizens of the world (more than 60%) will be living in these emerging cities in 2030. It will require finding adapted ways to manage urban growth and ecological transition in these developing systems. This global approach finally leads to the partition of the world we used in the book to analyze more precisely the evolution of individual national or continental urban systems.