Under what conditions do insurgents challenge gender norms? What do they gain by doing so? Using an original dataset of 137 armed groups fighting between 1950 and 2019, I show that 40% of rebel groups regulate civilian gender customs during conflict. This insurgent strategy is remarkably widespread, comparable to the provision of taxation or basic security in its prevalence (Albert 2022). Yet it is frequently omitted from cross-national research on rebel governance. This mixed-method project introduces new comprehensive data on 19 separate strategies of insurgent gender governance. From punishing domestic violence (9% of groups) to banning dowries (15%) to enforcing dress codes (11%), I argue that armed groups use gender governance to reshape local power relations. More specifically, I show that rebels exploit specific intra-community gender grievances in order to appeal to targeted sub-sections of the population and undermine local elites. This strategy allows them to increase control at a local level while reducing the likelihood of population-wide resistance. Combining cross-national analysis with four qualitative case studies examining Al-Qaeda in the Islamic Maghreb, Katiba Macina, the Eritrean Liberation Front (ELF) and the Eritrean People’s Liberation Front (EPLF), this project makes an empirical and theoretical contribution to the study of peace and conflict. Firstly, it draws attention to an overlooked source of insurgent legitimacy, deepening our understanding of how armed groups interact with the civilian population. Secondly, it improves our understanding of how gender inequality contributes to state fragility by highlighting the role of armed actors in this process. Finally, it expands our understanding of governance during conflict by highlighting the role of customary leaders, contributing to a growing scholarship on multilayered governance in areas of limited state-presence (Loyle et al., 2021).