Recent studies have begun to sketch the history of the Anti-Apartheid Movement in Britain, providing a convincing framework for understanding the transnational nature of the movement and its significance within the emergence of a global civil society. This article expands upon this work by exploring aspects of the ideological and the moral framework around which anti-apartheid sentiment began to crystallise in Britain in the late 1950s. Drawing on archival material from Church archives in both Britain and South Africa, as well as the expansive papers of the Africa Bureau, it focuses upon the activities of the well-known 'turbulent priests' who pioneered the campaign against apartheid in Britain: Michael Scott, Trevor Huddleston and Canon John Collins. It considers their status as the heirs of nineteenth-century humanitarianism before sketching the development of a Christian critique of South African racial policies during the 1930s and 1940s. The article then outlines the emergence of Michael Scott as a pioneer of anti-apartheid protest in the late 1940s, and his role in the parallel development of an international critique of South African policy and an embryonic language of human rights. In the early part of the 1950s, anti-apartheid protest evolved within the small and fissiparous British anti-colonial lobby, as its most vocal proponents began increasingly to articulate protest against apartheid in terms of solidarity with African political aspirations. The final section of the article describes how key ideological and strategic features of anti-apartheid protest were firmly established by the end of the 1950s.