Stefan Berger is Professor of Social History and Director of the Institute for Social Movements at Ruhr-Universität Bochum, Germany, as well as Honorary Professor at Cardiff University, UK. He is also Executive Chair of the Foundation History of the Ruhr. He has published widely on the comparative history of social movements, in particular labour movements as well as national(ist) movements, the history of nationalism and national identity, deindustrialisation studies, and memory studies.
Christian Koller is Director of the Swiss Social Archives (Zurich), Adjunct Professor of Modern History at the University of Zurich, and part-time Lecturer in Social History at the Swiss Open University. He has published widely on labour history, the history of racism and nationalism, historical semantics, sports history, the history of colonial armies, the First World War, urban history and in the field of archival and library sciences.