What exactly was and what role did pomerium play in ancient Rome? The study critically examines the definitions and individual functions that are commonly assigned to this limit. Again and again, the weak source base of apparent certainties of research and the overall interpretation of the Pomerium as the sacred city limits par excellence is revealed. In a new overall interpretation, Emmelius shows that the spatial regulation of practices was not central to the role of the pomerium, but the connection of urban space with learned knowledge and political symbolism.