This article examines the role of male youth in the political history of Dar es Salaam. ‘Youth’, as a category of opposition to elders, became important during the inter-war period as it was inhabited by educated African bureaucrats aspiring to representation in urban politics over the traditional claims of authority by local ethnic Zaramo and Shomvi elders. This group of bureaucrats grew in power through the popularization of racial-nationalist politics, and in the 1950s formed the Tanganyika African Nationalist Party (TANU), which instituted its own category of ‘youth’ with the creation of the TANU Youth League (TYL). Consisting mainly of young, under-employed men who failed to obtain sufficient educational qualifications, the Youth League challenged the late colonial state's theoretical monopoly over violence through voluntary and aggressive policing activities. After the work of independence was complete, there was practical way to demobilize this enormous, semi-autonomous police and intelligence-gathering force. The repeated reassertion of party control over its Youth League took many forms in the decade after independence – through the creation of a National Service and the militarization of development; frequent nationalist events and rituals where Youth League members controlled public space; and a war on urban morality led by Youth League shock troops. Control over youth also offered a potentially autonomous patrimony for ambitious TANU party members. The 1970s witnessed the beginning of the general failure of both state and party to generate sufficient resources to serve as a patron to patron-seeking youth, which has effectively decentralized youth violence and vigilantism ever since. A political history of ‘youth’, both as a social category and political institution, can shed further light on contemporary dilemmas of youth violence, meanings of citizenship, and hidden motors of party politics.