Over a 50-year span, Institute of Development Studies (IDS) research has not focused on cities or urbanisation to the extent it might have. We find that there is good reason for cities to now be described as the ‘new frontier’ for international development. In particular, violence is increasingly a defining characteristic of urban living in both conflict and non-conflict settings. This has important consequences for the relatively under-researched links between urban violence, the processes of state building, and wider development goals. Benefiting from key IDS contributions to the debates on the security–development nexus, citizenship and the hybrid nature of the governance landscape, we argue that the moment is opportune for the Institute to deepen its research and policy expertise on urban violence ‘in the vernacular’.