H. A. MacMichael was a member of the Anglo-Egyptian Sudan government between 1905 and 1933. This ethnographic work first published in 1922 is the culmination of almost twenty years' ethnological research conducted while H. A MacMichael was stationed in various parts of Sudan. This ethnography provides detailed histories of the origins, movements and degrees of relation between indigenous groups in Sudan based on oral histories gained from interviews with local people and Sudanese genealogical records known as 'nisbas'. These records provide a valuable insight into the construction and fluidity of ethnic identity at a local and regional level and have been widely used as a base for subsequent investigations concerning identity in Sudan.