The general practitioner as epidemiologist in Britain, 1930–1960

European and North American epidemiology changed in critical ways in the first half of the 20 th century, as experts increasingly turned to quantitative modelling and experimentation to answer key questions about virulence, endemicity, and immunity. As this article explores, however, British epidemiologists remained wedded to and advanced field-based epidemiological methods, developing these far beyond their origins in Victorian era outbreak investigation. Central to the advance of what I call community epidemiology was the work of William Pickles, who pushed epidemiological methods in data-gathering and visualisation through a long career as a rural general practitioner (GP). I demonstrate that in the period from 1930 to 1960, GPs created and adopted data-rich epidemiological ways of knowing that answered statisticians’ and modellers’ need for detailed spatial and temporal information, and that aimed to secure a place for GPs in the new system of national healthcare and research under the National Health Service (NHS) and the Medical Research Council.