Gustavo Giovannoni was a pivotal figure in twentieth-century conservation, yet his contributions to theory and practice are little known outside the Italian-speaking sphere. My project involves archival and field research documenting Giovannoni’s urban work (using material in the AAR archives and fieldwork in Italian cities where he worked) and interpreting its impact on conservation and urbanistic theory. Giovannoni’s contributions to urban conservation in the 1900s to 1930s marked a significant turn in the evolution of the field. Following Boito, he formulated a synthetic theory for managing historic cities, squaring competing nineteenth-century ideas about monuments (scrape/antiscrape) with the demands of twentieth-century urban design (the realities of growth and congestion). His nuanced strategy combined new construction, thoughtful conservation, and selective removal—diradamento (thinning, as with a forest)—reframing the problem of urbanism and monumentality and prefiguring recent attempts to theorize competing values of heritage and practice conservation at an urban scale.