Ugandan colonial authorities carved Bugisu and Bukedi districts out of Mbale district in 1954, isolating Mbale town as a separate entity. With ethnic tensions escalating as independence approached, Gisu and Gwere fought for Mbale's ownership. Empowered by decentralisation, Bugisu District Council pressed the colonial state to declare Mbale part of Bugisu, viewing the town as key to the region's wealth, and providing a symbolic status similar to that enjoyed by Uganda's leading ethnic groups. Gisu activists reinvented tradition as a tool of political advocacy, exerting hyper-masculine power over Mbale's non-circumcising Gwere residents through forcible circumcision. Gisu reformulation of a cultural practice within an urban struggle challenges previous categorisations of the Mbale case as merely another local obstacle to Uganda's peaceful decolonisation. Evidence analysed in this article contributes to a new understanding of East Africa's uneasy transition to self-government, and to the role of ethnic competition within late-colonial mobilisations more broadly.