Cities have emerged in different parts of the world in different periods of human history and the different trajectories of urban development have been inﬂuenced by culture, geography and world trade. Broadly speaking, we can distinguish a different pattern of urban development in the USA compared to Europe while countries such as Canada and Australia show a mix of European and American inﬂuences. Historically, the ‘western’ city has taken a different form to cities in Asia, Africa and some parts of Latin America. However, economic globalisation has begun to blur the distinctions between western and non-western cities and a similar trajectory of urbanisation has emerged within a host of underdeveloped countries. Urbanisation has proceeded at a faster rate in the developing world and it poses greater environmental and social challenges within the developing countries. At the same time, we have seen the emergence of a number of global megacities that interact more directly with each other than at any other time in human history. This chapter will trace different trajectories of urban development in different parts of the world in order to show that the ‘urban challenge’ takes different forms. At the same time, many of the environmental and social challenges posed by urban ‘sprawl’ are common and the chapter aims to demonstrate a universal need for much stronger city-wide planning and governance.