In 2015, the citizens’ platform, Barcelona En Comú won the municipal elections in the city of Barcelona. Emerging out of Spain’s anti-austerity and 15M movements, this activist led platform advanced a radically democratic political agenda. Between 2015 and 2019 they introduced a range of public policies aimed at empowering citizens through an expansion of participatory and economic democracy. This political programme included support for digital commons, urban commons and solidarity economy. Over the past three decades, the commons has featured increasingly as a subject in the political discourse of social movements. I argue that in the case of Barcelona, the commons has functioned as a bridging concept enabling political convergence among local movements. This anthropological research project set out to investigate the emergence of the commons as a political subject in the city of Barcelona. It asks a number of questions. What constitutes the social imaginary (Taylor 2004; Kelty 2008) of the commons? What does it mean to imagine and make the city as a commons (Foster and Iaione 2015)? Who imagines the city as a commons? What assemblages and networks of people, communities, activists, social movements, politicians and civic organisations make such political projects possible? What conditions of possibility, what social, institutional, historical and cultural factors lend themselves to imagining the city as a commons? The thesis explores continuities between the experience of social movements prior to 2015 and how they informed the policies and programmes of Barcelona En Comú. It considers how commoning practices have figured within movement practice and examines how apparently different social worlds, the worlds of free culture and techno-politics (digital commons), urban commons, and the solidarity economy, converged with the municipalist movement, and the political possibilities this afforded. In conclusion, I consider this convergence as part of a social movement project (Nilsen and Cox 2013), aimed at advancing a radically democratic vision of politics and economy.