For much of the twentieth century, a kind of dance has gone on between the forces that sought to regulate drugs, restricting their use to ‘medical and scientific’ purposes, and those who wished to consume them for entertainment and pleasure. This book maps out the movements of this dance in the classic years of the ‘British System’, a period that has hitherto been explored by historians only at its extremities, its beginning and its end. This chapter introduces the emergence and development of the white drug subculture in Britain. It contends that current views situating the advent of the subculture in the 1950s and 1960s are based on erroneous assumptions and readings. Instead, this subculture emerged during the interwar period. The 1930s, in particular, saw this subculture crystallising from upper-class bohemia and the nightclub world of London’s West End. The role played by the prescribing doctors of the ‘British System’ was a key component.