The aim of this volume is to explore again the notion of generation, which is of very common use in political science. It relies on a sociological definition inspired by Karl Mannheim. According to him, age cohorts don’t always form a sociological generation. It requires not only people linking with the same events and having the same experiences during youth, but also that these experiences take place in the same historical and social background. Starting from the political institutions rather than from the events labeled as “political” in the media and in the dominant discourse, this volume puts under scrutiny the generational socialization of some not very visible populations. It invites us to study, behind the so-called “generation conflict”, the political work of representing and mobilizing different generational groups.