Isabelle Sommier is Full Professor of Political Sociology at Paris I Panthéon-Sorbonne University, former director of the CRPS (Centre de recherches politiques de la Sorbonne) and currently Deputy Director of the CESSP (Centre européen de sociologie et de science politique, a fusion between CRPS and CSE Bourdieu institute). She has published on the theory of social movements, political violence, radicalization and terrorism.