How do the visions of the state articulated by armed movements during conflict change when they become political parties after war? We show that ideas about the state are often central to the strategies and direction of these new parties, but there is variation in the extent to which these ideas have changed. The first part of this article shows why a focus on former rebel parties provides valuable insights into the role of ideas in post-war politics. The second part draws on the literatures on civil wars and political parties to highlight their relevance for former rebel parties. The third part provides a framework for understanding the variation in the role of ideology in former rebel parties, by focusing on ideological content and explanations of post-war ideological continuity and change. This part also introduces the other articles in the special issue and wider collection. Finally, we discuss the effects of these ideologies when they encounter other logics of post-war politics.