'Few researchers and fewer policy makers realise that the most serious danger lurking in African states' growing administrative capacity to identify and track their citizens is the development of a permanent architecture of ethnicised citizenship. Sam Balaton-Chimes' Knowing Ethnicity is the best account of why this happened and what is at stake in reproducing it.' Keith Breckenridge, Wits University 'This rich, detailed book offers important contributions to studies of governmentality, social sorting, and legal recognition; census, registration, and identification technologies; and the pre-history of datafication. Through her concept of 'cultivated vagueness' and with a sensitivity towards the diverse strategies of minoritized groups and their representatives, Samantha Balaton-Chrimes provides refreshingly new insights into long-standing debates about the making and politicization of ethnicity in Africa. In dispelling the myth that there has ever been a definitive list of Kenya's '42' ethnic groups, Balaton-Chrimes offers fine-grained analysis of the politics of 'code seeking,' 'the arts of government and of being governed,' and the risks and opportunities that emerge in the disconnect between law and practice, which has implications well beyond the field of African studies.' Keren Weitzberg, Queen Mary University of London