In late nineteenth century Britain traditional coaching structures came under pressure as increasing class differentiation led to a rejection of professional coaches by the middle-class organizers of National Governing Bodies (NGBs), who employed regulatory definitions to exclude them. Their social position within the class hierarchy, combined with their attachment to an amateur ethos that rejected specialization and professionalism, empowered British administrators to develop a culturally specific master-servant relationship with professional coaches that persisted until long after the second world war. This presentation illustrates the essential characteristics of British professional coaching in the first half of the twentieth century through the biography of Bill Thomas, coach to Oxford University in the inter-war period, whose career highlights the subservient role that he played within British athletics, despite the many successes of his athletes. Drawing on a range of sources, combining the traditional use of newspapers, texts, directories, and organizational records, with census data, probates, and other genealogical material, his coaching career is presented as an exemplar of the working life of an archetypal British professional coach in the first half of the twentieth century.