Excavation has increasingly highlighted aspects of the continuity of settlement from the fourth into the sixth centuries. This paper offers an additional set of evidence to show that continuity of the field and cropping units associated with settlement is also detectable from this period using excavation, landscape and later manuscript evidence. The recognition that some late Roman ditches underlie later medieval headlands of open:field systems has been well explored already. In the east Midlands area of Northamptonshire and Cambridgeshire recent work indicates that in some cases a fossilization of Roman _fields took place. 71wt fossilization is indicated by areas of small medievalfurlongs associated with sites oflate Roman and early medieval date, and could indicate continuity within the farmed landscape with little intermption to the farming system.In the last twenty years archaeological excavation and extensive field-walking programmes in the areas of the middle and lower Nene valley of north-east Northamptonshire, northern Cambridgeshire and the lower Weiland valley have shown increasing numbers of sites where late Roman and early medieval material suggests a continuity of occupation. Until now it has been thought possible to deal with the transition from Romano-British to early medieval on sites only from the evidence of changes in pottery, building character and layout. The traditional massproduced ceramic wares of the fourth century cease with the supposed arrival of migrant families who introduced their own styles and forms of vessels that were handmade with markedly different fabrics and decorative forms. New traditions of pottery also heralded new building forms of wood and thatch which replaced the Roman stone-built structures. Personal items, such as brooches, pins and weaponry, also show marked differences between the fourth, and the fifth and sixth centuries. This supposed changeover is still poorly understood and relies on the traditional view of a 'replacement' population with all of the problems that it entails. To some scholars the 'Saxon invasion and settlement appear more as the political take-over of a disintegrating society rather than a mass replacement' (Taylor I983, I I I).Recent work presented within this paper has attempted to examine different aspects of the available evidence and link sites which exhibit a continuity from late Roman to the fifth century with later medieval and post-medieval field layouts. Such field systems demonstrate that there is, in some cases and in isolated areas, evidence to show that the shape and size of medieval and post-medieval furlongs may perpetuate the Roman fields which had continued in use through to the fifth and sixth centuries. These fifth-and sixth-century fields later evolved into more developed field systems. Such field systems are well attested in many parts of the country by the ninth century.Downloaded by [Nanyang Technological University] at 03: