This dissertation examines the implications of leadership change on political activism in authoritarian regimes. It asks and answers the question, “Why do some leader transitions induce significant societal activism while others pass without the commotion of contentious activities?” Previous research examines leadership succession as an elite-level event. Instead, this dissertation argues that succession should also be understood as a relational event involving both government and society. Existing research also tends to focus on how emergent leaders are selected and take power, whereas this analysis sees leader succession as a causal event that affects government-activist interaction. The core argument is that authoritarian leader changes often stimulate the public expression of demands and grievances, but the extent to which they do so is influenced by differences in how leaders change and the institutional context in which transitions takes place. This effect arises because the transitional period introduces uncertainty into the relationship between state and society, an uncertainty that incentivizes societal activism and creates opportunities for activists to test boundaries and express demands and grievances. The dissertation assesses these claims through multiple methods, including (1) cross-national, quantitative analysis of all national leader changes from 1950-2014, and (2) case studies of leader transitions in Jordan (1999) and Syria (2000) that combine qualitative data from interviews and archival materials with quantitative analysis of contentious events coded from newspaper reports in the years surrounding these successions. The findings demonstrate that leader succession creates an environment that invites contentious activism, but that this “succession-contention connection” is moderated by characteristics of the succession itself and the political institutional context in which it occurs.