Roy Dilley is Professor of Social Anthropology at the University of St Andrews. His books include Islamic and Caste Knowledge Practices among Haalpulaaren (2004), Nearly Native, Barely Civilized: Henri Gaden's Journey Across Colonial French West Africa (2014) and Rencontres photographiques: Henri Gaden, photographe, en Afrique Occidentale, with the Archives nationales d'outre-mer, Aix-en-Provence.