This paper presents the results of a pilot project investigating the potential of archaeological sites and finds to reveal how the Gewisse – the progenitors of the West Saxons – emerged to form the first post-Roman polity in the upper Thames valley. Digital mapping of Portable Antiquities and other data has revealed new ‘hot spots’ of activity dating to the period between 400 and 750, as well as gaps in the distribution of early Anglo-Saxon material culture that could point to a British presence. The distributions of certain categories of object, such as imports and precious metals, hint at the existence of a distinct ‘riverine’ cultural zone with links to east Kent. New possibilities for understanding the formation of fifthcentury identities and calibrating fifth-century chronology are explored, as is the evidence for the emergence in the late sixth- to mid seventh-century of great hall complexes, notably at Sutton Courtenay and Long Wittenham, for which new evidence is presented. The potential for identifying minor routeways and understanding how these may have conditioned the location of early medieval settlement in the region is also considered.
