Aurélie Andry is an Alexander von Humboldt experienced researcher in the Institute for Social Movements at Ruhr University Bochum, Germany.Stefan Berger is Professor of Social History and Director of the Institute for Social Movements at Ruhr University Bochum, Germany. Along with Holger Nehring and Nikolaos Papadogiannis, he edits the book series, Palgrave Studies in the History of Social Movements.Sophia Friedel is a Research Associate in the Institute for Social Movements at Ruhr University Bochum, Germany.Frank Georgi is Professor of Contemporary Social History at Évry Paris-Saclay University, France, and Deputy Dean of the Graduate School Humanities - Heritage Science at Paris-Saclay University.