Over the past thirty years, one of the fastest growing fields of urban history has been the history of planning. In some respects, this is surprising, as urban planning had existed on an institutional basis only since the early twentieth century. In other ways, though, it was a very logical development. Planning reached its high point during the 1960s, and by the 1970s was being condemned in many quarters, being blamed, for example, for disasters like high-rise tower blocks and sacrificing old cities to crude commercial and transport developments. Historical research was necessary to understand how a movement which promised so much at the start of the century had degenerated so badly in sixty years. Criticism became so severe that, in the words of one historian, ‘many planners have certainly thought in more pessimistic moments . . . that the past may be the only thing they have to look forward to’. For whatever reason, the Planning History Group was set up in 1974 and a massive body of historical research on planning has been produced. This paper reviews four recent books on planning, two from North America and two European. They represent different aspects of planning and different time periods and will be treated in chronological order.