London has become the global city above all others. Money from all over the world flows through it; its land and homes are tradable commodities; it is a nexus for the world's migrant populations, rich and poor. Versions of what is happening in London are happening elsewhere, but London has become the best place to understand the way the world's cities are changing. Some of the transformations London has undergone were creative, others were destructive; this is not new. London has always been a city of trade, exploitation, and opportunity. But London has an equal history of public...