Associazione Internazionale di Archeologia Classica
Abstract
This publication focuses on the site of Monte Giulio (Fiumicino, RM, Italy), the complex that makes up the internal (eastern) delimitation of the harbour basin of Claudius, investigated through a series of cores, trenches and excavations between 2007 and 2009. We recognized various natural and anthropical phases, from the construction of the structures on Monte Giulio in the Trajanic period until the end of the occupation of the area, dated not beyond the beginning of the fifth century. Hypotheses are put forward as to the extension and the limited depth of the interdunal lagoon located in pre-imperial times behind the coastline north of the future harbour of Trajan, and on Monte Giulio as a complex functional for small-sized boats, constructed on a natural dune ridge in this lagoon. Moreover, hypotheses are put forward on the general environmental conditions of the area in pre-Roman and Roman times, and on the probability that Claudius did not dredge the entire lagoon, but may have done so only locally through the excavation of channels in the bottom; he then cut through the coastal barrier to let the sea enter, and concentrated the maritime traffic on Portus through the creation of harbour structures along the original coast line. On the basis of the excavation data, the sea level in the second century AD results to have been more than one meter below the present level, and rising continuously in the centuries thereafter. Integration of new radiocarbon datings with those known from literature has confirmed that the shift of the Tiber mouth from north to south has occurred most probably in the eight century BC or slightly later
