No attempt to evaluate the longue durée of human settlement can ignore the environment as both a formative influence and as a cultural artefact. The environmental programme of the project collected data to complement the regional geomorphological and palynological record on patterns of landscape change in response to climate change and the influence of human activities. The geomorphological fieldwork focused on the catchment of the Marta river that flows from Lake Bolsena past Tuscania to the Tyrrhenian sea near Tarquinia. The Late Glacial environment c.15,000 years ago consisted of a steppe landscape.After a sedimentary hiatus in the Early and Mid Holocene, sediments started to be laid down again in the Later Etruscan period c.500-300 BC, reflecting the extensive nature of Etruscan agriculture.Significant human impacts began in the Roman Republican period. Then and during the Early/Mid Imperial periods the Marta and other rivers in the area were unstable braided and wandering gravel-bedded rivers quite unlike the modern rivers. Their dynamism largely reflected a colder wetter climate than today but also woodland clearance and increased arable cultivation.This combination pre-conditioned the landscape’s sensitivity to alluviation in the Late Medieval and Post Medieval periods.