This article analyzes the transformation of an image of ritual violence on the Kenyan coast from the sixteenth century to the present. Drawing on a range of sources, it shows how understandings of “mung'aro” — a ritual of senior male initiation among Mijikenda-speaking peoples — changed as it became an object of inquiry for generations of missionaries, explorers, colonial administrators, local intellectuals, and foreign historians and anthropologists. In the mid-twentieth century, mung'aro became a key feature of Mijikenda traditions of origin in Singwaya, but in such a way that it reversed the direction of a specific form of ritual violence described in nineteenth-century traditions. By focusing on the transposition and recombination of ritual motifs across practical and discursive modalities (namely, ritual and narrative), this article offers a new approach to “the limits of invention” regarding traditions of origin.