This project brings a novel approach to minority issues through the analysis of arguments, actors and practices at the League of Nations. The LoN system of minority protection, along with its influence in global frameworks (self-determination, specific jurisprudence), has been analyzed frequently, but questions of how minority issues were collectively constructed and debated in an evolving inter- and transnational arena have not been taken up to the same extent. Nevertheless, the analysis of intermediate activities and micro-decisions (responses to minority petitions, NGO proposals, expert reports) helps one to better grasp different interpretations of minority issues and the tensions between them, notably between those where (national) cohesion required cultural homogeneity and those giving minority protection a basic role in reconciling citizenship and identity. The project is based on archival work and sociological and historiographical cross-analysis of practices of League personnel and selected minority organizations, NGOs, state officials, and experts. It is aiming at a reconsideration of scientific approaches to minority questions, as well as the implementation of a multi-actor methodology, and more generally at stimulating renewed debate on minorities and national identity.