Whereas rents in conquest petrostates have been a source of relatively peaceful authoritarianism, this has not been the case in many Muslim countries that do not produce oil. Muslim non-oil producers – many of whom were also exposed to the institutional legacy of Muslim conquest – have tended to experience more frequent and violent political upheaval since the 1960s. This chapter leverages a quasi-natural experiment of oil price driven foreign aid disbursements to show that buoyant levels of foreign aid receipts strengthened dictatorship in Muslim non-oil producers, but their subsequent decline led to heightened political instability in the form of civil war. However, despite this greater political upheaval (during periods of lower aid inflows), Muslim recipients remained staunchly non-democratic