The IPHS conference in Yokohama demonstrates that the history of planning is in rude health. The discipline now includes the histories of planning around the world, and scholars from many different countries are reflecting deeply on their own and each other's experiences. Planners, the institutes they work in, the evolution and transmission of their ideas and of course their application and success or failure are now considered from a multitude of regional and disciplinary perspectives. The vitality of these debates in the twenty-first-century global urban world holds much promise that historical study can contribute to understanding some of the challenges facing contemporary cities.