This paper by Martin Legassick is one of three that the scholar and political activist presented to the Southern African Seminar at the Institute of Commonwealth Studies, London University, in 1972-3. Though widely influential and often cited in academic works, none has been published before and all are ‘unfinished’. The historiographical importance of this paper lies in its location of the origins of segregation in terms of British imperial policy in the decade after the South African War of 1899-1902. Legassick shows how the British conquest of South Africa created unprecedented opportunities for the rational administrative and political ‘reconstruction’ of the former British colonies and Afrikaner republics. Central to the vision of the new South Africa was a concerted attempt to define ‘native policy’. The South African Native Affairs Commission of 1903-5, headed by Sir Godfrey Lagden, represented a key document in this regard. It served to articulate some of the main premises of what later emerged as ‘segregation’: territorial separation between whites and blacks; a controlled flow of cheap African labour to the white cities and mines; and a political system that excluded Africans from direct representation in government. Legassick locates core elements of segregationist theory within wider imperial debates. And he indicates that these ideas retained influence in the interwar period when segregation was fully realized and implemented by an Afrikaner-led government.