This research project is devoted to the study of the different faces of populism and illiberalism worldwide, both in their contentious politics and their movements’ actions once in power. It follows in particular the evolving situation in Western and Central-Eastern Europe, as well as in the US. It shares the consensus definition of populism as both a “thin” ideology and a communication tool, and sees it as a dynamic (both bottom-up and top-down) process. It also advances the notion of illiberalism as an alternative concept that moves the needle toward a backlash against various currents within liberalism.