This thesis offers a materialist account of political action from the perspective of the aesthetic, focusing on a global day of action, protest and carnival staged to coincide with the G8 Summit on June 18th 1999. An event known as J18. Part One begins with a review of contemporary literature concerning the sociologies of contemporary political movements, theories of space and locality provided by geography, analyses of public interventions by art practice as well as the tactical deployment of media and writing related specifically to the cultural politics of anti-capitalism. The theory and methods chapter surveys historic shifts in thinking about political action, through an attendant Marxist epistemology, through three key events: the Paris Commune, the Russian Revolution and May 1968. The search for a materialist understanding of political action feeds the act of drawing together empirical material from J18 by way of the data gathering process and the reciprocal development of a critical framework used as a method of interpretation. In Part Two a multi-centred account of the event is narrated by way of micro-examples that are each affectively attuned to, and constitutive of the events happening.