The changing face of the eastern Caelian in the 1st–4th centuries AD: work by the Rome Transformed Project

In addition to arguing that advances in digital technologies can facilitate step changes in how to visualise and debate the dynamics of Roman urbanism, the paper suggests that the experience of the Rome Transformed project offers some other general lessons. At a generalised level, the ebb and flow of development in the eastern Caelian accords with the well-attested phenomenon of the ‘fringe belt’, a dynamic area as integral to the story of large cites as any of other aspect of the panoply of urban infrastructure. More specifically, though, we can see in this area the playing out of what are clearly key themes in evolution of the Roman empire’s cities, notably in the nuanced adaptation of sophisticated engineering strategies, here deployed on monumental scale, to landscape transformation. Without its hydraulic engineers, without its terraces, without its concrete substructures, the city could never have undergone the pattern of transformation it did. This has multiple implications of course, and opens areas for new experimentation such as, for example, the palatial complex of the Sessorian, the design of which arguably pioneers its own model of urbanistic enclave. By the late 3rd century AD, the eastern Caelian has acquired – within wider Rome – what has become an essential urban characteristic, an enclosing wall, and, in the course of time, this is adapted to situate the pomp and procession of Late Antique ceremonial. The capacity of ecclesiastical centres to generate new forms of growth is also a dominant theme emulated across much of the empire, fostering a new kind of urban life, as the pulse of Classical cities weakened. There are also features that are more particular to Rome. As has been argued, the Severan transformation plays a key role in the longer-term evolution of the area, and while the fundamental role of the military in this may seem at a variance with general trends in Italian urbanism under the empire, it connected with currents elsewhere, notably urban development on the Danubian frontiers, and with the particularities of Rome itself. At one level, seen especially from the perspective of changes in land ownership, it can be seen as a successor to a process specific to the power play of the City of Rome’s peripheries from the Principate onwards. The uniquely dynamic nature of Rome’s horti is intimately linked to Roman power politics, as places where wealth might be displayed and influence pedalled. In such an environment, it is scarcely surprising that sometimes through inheritance, and sometimes through outright brutality, successive imperial proprietors and agents acquired steadily more land requiring, and facilitating, a new environment open to new forms of development.