What is urban violence? Challenging the implicit answer that normally accompanies this question (i.e. the violence that takes place in the city), this talk embarks on a genealogical endeavour to unpack the where and the when of urban violence. The underlying presupposition is that the notion of urban violence surfaces at a specific historical and geographical juncture, namely at the dawn of urban modernity. In this context, the processes of urbanisation, industrialisation, and colonisation have been complemented by the surfacing of a novel urban imagination, and a new set of (bourgeois) aesthetic expectations about how (comfortable) urban life should look and feel like. After presenting the book project from which this intervention originates [Urban Violence. Security, Imaginary, Atmosphere (forthcoming 2023, Lexington), co-authored with Simone Tulumello (ICS, Lisbon)], the argument will be developed through the help of 19th century Catalan urban planner Ildefons Cerdá, and 20th century philosopher Peter Sloterdijk.