Between Claudius and Trajan: Palaeoenvironmental Evolution of the Imperial Port of Portus (Central Italy)

Abstract

The port of Portus was located about 30 km southwest of Rome and was the most important in theWestern Mediterranean during the Roman Imperial period (27 BCE–476 CE). This paper analyses the palaeoenvironmental evolution of the channel linking the outer harbour, or Claudius Basin, with the inner harbour, or Trajan’s Hexagon. During the 1st century CE, this area was situated in an open marine environment, which gradually became more confined due to sedimentation from the River Tiber and the silting caused by the massive accumulation of fibres and leaves from the seagrass Posidonia oceanica. In the ~2nd–5th centuries CE, the area transitioned to a brackish environment and eventually became silted up, with a marked decline in port activity from the 5th century CE onward.