This chapter shows the exercising of power in action in the public space. It looks at who ‘owns’ this, the Christianization of it in Rome, and the increasing role of the papacy in appropriating and in running it, revalorizing it as part of Rome’s Christian past and present, expressed through pilgrimage. This appropriation is contested by the secular aristocracy, which in turn appropriates the public space and rewrites the topography of the city in the tenth century. The use of the public space as an area of either social cohesion or conflict is studied, through the ceremonies, elections, oaths, processions, assemblies, justice and defence meetings; but also riots, conspiracies, and contested elections. This space of cohesion or conflict is fundamental to the creation of the unity and sense of identity of the city, especially around the patron saint or, sometimes, around or indeed against an imperial ruler