The research project examines ‘charismatic’ leadership in social movements, a subject that has been neglected by historiography since Max Weber’s conceptual notes at the beginning of the twentieth century. The focal point is the Belgian labour movement in the interbellum. After the first generation of charismatic leaders at the end of the nineteenth century, a new generation emerged, which, with its preference for a nationally oriented authoritarian socialism, gave a new dimension to Weber’s charisma theory, founded on syndicalistic and anarchistic Gesinnungspolitiker. Comparing those generations with and testing them against a comparable form of leadership in Europe between the two wars, lends the project an international dimension. In contemporary history, combined with political leadership, charisma is a problematic notion that requires conceptual clarification before historical contextualisation and transnational comparison. It is often assumed that charismatic leadership manifests itself primarily in times of crisis. It is also frequently associated with social movements demonstrating a certain nostalgia for pre-industrial and pre-democratic values. In the first part of the project, the Weberian notion of charisma is problematised by means of a thorough status quaestionis of the historical and sociological study of this concept to date. In the second section of the project, Hendrik de Man’s leadership is used as an empirical case study to operationalise the charisma concept in relation to the socialist movement during the interbellum. Using a variety of sources, the researcher aims at analysing 1) Hendrik De Man’s changing relationship, as a charismatic leader, with the socialist rank-and-file, during the subsequent phases of his career; 2) the influence of his conceptualization of mass psychology on his political style and performance; 3) the comparison of De Man with Belgian predecessors, such as Edward Anseele and Emile Vandervelde, and with similar political leaders in other countries such as Koos Vorrink, Gustave Hervé and Robert Michels.