Selection of pieces of horse harness decorated in styles of Celtic art from the Roman fort of Newstead ©NMS
Impact went beyond the movement of Roman goods, and was not a unidirectional process. It has been argued that the apparent growth in production of objects adorned with 'Celtic art' around the Roman conquest is an expression of indigenous identity in the face of the threat of Rome (MacGregor 1976, 177-8; Hunter 2007b). This example also highlights the complicated interactions involved - for such Celtic art became a crucial influence on the hybrid styles of material culture (especially decorative copper alloys) which emerged in the frontier zone. These Romano-British art styles can be seen as a form of frontier art, the indigenous art no longer 'barbarian' or 'Celtic' but a key part of emergent frontier culture, used on both sides of the frontier by military, civilian and indigenous groups (Hunter 2008). Investigating this material, and trying to understand its development and meaning in different contexts, is an important way to an understanding of the changing societies of the frontier zone.
There are also more specific examples of material moving south, from barbaricum to the frontier. Petrographic analysis of so-called 'Local Traditional Ware' pottery, which used Iron Age technology but was influenced by Roman forms, has shown that finds from the east end of Hadrian's Wall came from north Northumberland (Bidwell and Croom 2002, 169-172); it was perhaps sought after for its contents which may have included salt. Scottish assemblages should be checked for similar phenomena. There is evidence of the movement of other small-scale luxuries south, such as ornaments of black organic stone and perhaps of multi-coloured lithomarge (Allason-Jones and Jones 1994; Stevenson and Collins 1976).
Styles of 'Romano-British' material culture, such as metalwork (e.g. brooches) and glass bangles, merit renewed study in the light of recent theoretical approaches to investigate the contexts in which they emerged.