This thesis considers the cultural and political geographies of British humanitarianism during the fifty years following the Berlin Conference of 1884-5, focussing on two societies which merged in 1909: the Anti-Slavery Society and the Aborigines Protection Society. This period in the history of the Societies has received relatively little scholarly attention. On the one hand, historians of anti-slavery have focussed overwhelmingly on the late eighteenth and early nineteenth centuries. On the other, scholars of modern human rights have concentrated their attention on the period following the Universal Declaration of Human Rights in 1948. This thesis aims not only to bridge this gap, but to bring thesis literatures — on anti-slavery and human rights — into productive dialogue. The thesis has three major themes. Firstly, it situates the two Societies within a wider 'humanitarian complex' that includes pan-Africanists, missionaries, feminists, social reformers and others, exploring the connections and the tensions between these groups. Secondly, it considers the imaginative geography of British humanitarian concern during the period under study, which involves both a global mapping of the humanitarian gaze and the discussion of the politics of representation. Thirdly, it examines the repertoire of practices which humanitarians developed in their campaigns to bring slavery and other humanitarian abuses to the attention of various different publics. The thesis is organised into seven chapters. Chapter 1 establishes the theoretical framework for the study, drawing especially on the work of Catherine Hall. Chapter 2 provides an historical context for British humanitarianism between 1884 and 1933. Chapter 3 considers the humanitarian complex. Chapter 4 examines the role of the journals published by the two Societies in bringing humanitarian issues to the fore. Chapter 5 investigates the models of empire imagined by British humanitarians. Chapter 6 provides an account of the celebrations organised by the humanitarian movement in 1933 to mark the centenary of the abolition of slavery in the British colonies. The thesis concludes by exploring the relationship between British humanitarianism in this period and its modern equivalent.