This is a cultural history of borders, hygiene and race. It is about foreign bodies, from Victorian Vaccines to the pathologized interwar immigrant, from smallpox quarantine to the leper colony, from sexual hygiene to national hygiene to imperial hygiene. Taking British colonialism and White Australia as case studies, the book examines public health as spatialized biopolitical governance between 1850 and 1950. Colonial management of race dovetailed with public health into new boundaries of rule, into racialized cordons sanitaires.