This project examines the topographical evolution of Rome’s Subura district during the first millennium AD. Ancient literary accounts describe a persistent elite occupation on the upper slopes of the city’s eastern hills, but the valley between them is described as a socially marginalized, crowded residential and commercial area. Since the archaeology of the urban lower class has rarely been of great interest to scholars of Rome, we have an abridged reconstruction of the city’s historical topography and an incomplete understanding of how the lower classes actually lived. My dissertation fills this gap, as it is the first systematic study of the area. In analyzing the district over the longue durée, its shifting character and fabric can be tied to the drastic social and religious changes that took place during the first millennium.