ABSTRACT
The archaeological remains of the frontier of northern Britain and the trends identified have been interpreted as evidence for increasing regionalization and localization of the frontier communities through the 4th and 5th centuries. Though this is a robust interpretation, similar trends may be visible in other frontiers of the late Roman West and East. No frontier should be considered in isolation, but the unique circumstances and history of each frontier must also be accounted for. Regional variation in the limites is apparent from the establishment of each frontier, as the physical form and disposition of military installations between each frontier varied according to topography, supply and economic concerns, and any external threat that the frontier was intended to defend against. The later 3rd century saw the development of the Saxon Shore system along the coasts of southeastern Britain and northern Gaul. By the 4th century, the rivers Rhine and Danube were the foci of frontier defense on the continent (Maxfield 1987), whereas the liminal zone between the Sahara desert and the rich northern lowlands provided the same focus in North Africa (Daniels 1987). These Western frontiers remained geographically stable from the late 3rd into the early 5th century. The Eastern frontiers were generally fixed, but the proximity of and periodic tensions/conflict with Sassanian Persia meant that the border shifted periodically (Parker 1986: 6–10). The physical geography and climate of the Eastern and North African frontiers, bound by desert, was a defining characteristic of these frontiers, such that control of roads and access into agricultural regions provided focused tactical and strategic concerns. Britannia did not have an obvious focus of a natural feature, like a desert or large river system, so the Wall itself provided a built focus for the frontier.
