The advent of Islamist rebel governing projects in different regions of the world provides an opportunity to link the empirical study of these groups with the broader, emerging academic literature on rebel governance as well as studies of political Islam(s) and religion and violence. This paper seeks to do just that through its central case study, the Somali Sunni Islamist insurgent group Harakat al-Shabaab al-Mujahideen (Al-Shabaab). Drawing on primary sources from Al-Shabaab, the paper traces the group’s governing project from its origins in 2008 up to the present day, paying particular attention to the foundational years (2008-2010) when its civil administration was being set up. The territorial governance projects of Islamist rebel groups, like those of non-Muslim rebels, include a wide range of activities including the distribution of food and material aid, implementation of a system of law and order, mediation of civil disputes, and construction and agricultural projects. As part of their proto-state governance projects, Islamist rebels construct and deploy symbols and symbolic repertoires that advance the group’s claim to symbolic sovereignty and legitimate sociopolitical authority in a systematized language that is meant to resonate more deeply with local audiences than a naked display of insurgent power or a system of exchange based on material incentives alone. Symbolic repertoires and the use of symbolic power allow Islamist rebel rulers to advance their governance ambitions and claims of legitimacy within a defined narrative frame, imbuing them with added historical and religious legitimacy through the inclusion of specific symbols and performance of specific rituals such as congregational prayers, communal religious festivals, reconstructing local education systems, and couching insurgent shariʿa-based ‘justice’ within a theological as well as legal framework. This paper considers how Al-Shabaab as a governing organization uses symbols and symbolic power as a form of soft power as part of a socialization process within local communities in rebel-held and rebel-influenced territory.