The starting point of my book is straightforward: military coups have been the main causes for autocrats’ downfall globally throughout the twentieth century. Consequently, the survival of nondemocratic leaders in coup-prone countries is above anything else a function of successful coup-proofing. I show how frequent coups have been in developing countries following decolonization, but also, how harsh the fate of fallen leaders have typically been following military takeovers – particularly in the Arab world. To coup-proof, autocrats used ideational factors (i.e., fostering shared aversions); or material factors (i.e., counterbalancing; promoting the material interests of senior officers; divide-and-rule tactics); or combinations of both. I show how coup-proofing tactics structure civil–military relations differently, but also, amplify or reduce vertical and horizontal rifts in officer corps. I then link these variations to military behavior when popular uprisings challenge the authoritarian status quo.