A programme of improvements to the A421 south-west of Bedford carried out by Balfour Beatty Civil Engineering Ltd on behalf of the Highways Agency afforded Oxford Archaeology an opportunity to investigate early settlement along a corridor of the clay landscape of Marston Vale, within the catchment of the River Great Ouse. The investigations comprised nine areas of excavation supplemented by watching briefs and earthwork surveys of three historic boundaries, as well as geophysical survey and field evaluation at a site that was not ultimately excavated. The Vale appears to have been visited only occasionally during the early prehistoric period, the evidence being limited to a sparse distribution of worked flint and a single cremation burial dated by radiocarbon to the early Iron Age. The majority of the remains uncovered dated from between the middle Iron Age and the late Roman period, and were consistently rural in character, consisting of a series of small farming settlements. The report describes the evolution of settlement within the Vale as evidenced by the changes to settlement forms, landscape organisation, economic strategies and material culture, brought about by the effects of an increasing population and the imposition of Roman rule. The level of activity declined during the late Roman period, and the remaining settlements were abandoned during the early part of the 4th century.