Theories of rebellion and revolution neglect short-run processes within state structures that can undermine their internal cohesion. These processes are evident in the rapid unraveling of the Chinese state early in the Cultural Revolution. Portrayed in past accounts as a culmination of student and worker insurgencies, an early 1967 wave of power seizures was in fact accelerated by an internal rebellion of bureaucrats against their own superiors. These led to the widespread collapse of local governments, diverting the course of the Cultural Revolution and forcing intervention by the armed forces. An event-history analysis of the diffusion of power seizures across a hierarchy of 2,215 government jurisdictions portrays a top-down cascade that spread deeply into rural regions with few students and workers and little popular protest. The internal rebellions were generated endogenously by events during the course of these upheavals, as individual officials reacted to shifting circumstances that threatened their positions.