Book excerpt: The urban century manifests itself at the peripheries. While the massive wave of present urbanization is often referred to as an 'urban revolution', most of this startling urban growth worldwide is happening at the margins of cities. This book is about the process that creates the global urban periphery – suburbanization – and the ways of life – suburbanisms – we encounter there. Richly detailed with examples from around the world, the book argues that suburbanization is a global process and part of the extended urbanization of the planet. This includes the gated communities of elites, the squatter settlements of the poor, and many built forms and ways of life in-between. The reality of life in the urban century is suburban: most of the earth's future 10 billion inhabitants will not live in conventional cities but in suburban constellations of one kind or another. Inspired by Henri Lefebvre's demand not to give up urban theory when the city in its classical form disappears, this book is a challenge to urban thought more generally as it invites the reader to reconsider the city from the outside in.