How did Western colonial rule affect political institutions in Africa? Although a rich historical literature examines the philosophy and practice of indirect rule in colonial settings, we have little systematic evidence about how the aims of colonizers interacted with the structure of indigenous institutions to shape local governance patterns. We first explain why it is usually optimal for colonizers to delegate authority to whatever institutions were already there, even in historically decentralized areas. We then analyze originally compiled data on African institutions in the precolonial and colonial periods for nearly 500 subnational units across British Africa, focusing particularly on the presence of executive constraints in the form of councils. Colonial councils were widespread, reflecting precolonial precedents. Early agents who lacked traditional authority often failed to keep the peace and raise revenue in a context of rapid socioeconomic change. Pressure from below prompted British officials to re-introduce systems of executive constraints based on precolonial models.