In her introduction to London: Aspects of Change (1964), Ruth Glass wrote that the city was “too vast, too complex, too contrary and too moody” to be known entirely. The same could be said about Glass herself, an urban sociologist based at University College London from the 1950s to her death in 1990. She left no archive for scholars to sift through. The term she coined, gentrification, has become ubiquitous, but she remains out of sight. Her longtime friend, the late Marxist historian Eric Hobsbawm, described her as a “tiny, combative, bird-like woman.” Yet even beyond coining gentrification—the term that outlived her—Glass set the agenda for a generation of postwar social scientists, breaking new ground in both the study of race relations and in community studies.