3.6 From the end of the Antonine Wall to the Severan invasions

Oblique aerial view of Carpow fort © RCAHMS

The new frontier arrangements were different from those in place during the first phases of Hadrian's Wall (Breeze 1982, 136-40). North of the Wall there were still three outpost forts to the west, at Birrens in SW Scotland, Netherby and Bewcastle in England. Now, however, there were complementary arrangements to the east. Forts remained in occupation along Dere Street running north from Hadrian's Wall at Portgate. These appear to have extended as far north as Newstead and may have included Cappuck, and perhaps Inveresk (Breeze, in press; Bishop 2004, 185). These most northerly forts appear to have been abandoned in about 180. It is likely that the frontier unrest of that time resulted in a reappraisal of Hadrian's Wall and the forts to its north. While these changes are often dated to the early third century and are regarded as a re-organisation of the northern frontier by the Emperor Caracalla, there are indications that some arrangements were already in place before that time, and it is possible therefore that they date to the post-180 settlement.

The post-180 arrangements included the basing of a thousand-strong mixed infantry and cavalry unit at Risingham and High Rochester on Dere Street with a couple of 'irregular' units. Scouts were probably also based at Netherby, called Castra Exploratorum, while a thousand-strong unit appears to have been at Bewcastle; Birrens was abandoned (Breeze 1982 , 136-140). The purpose of these arrangements was presumably to allow the army to maintain watch over the lands well to the north of Hadrian's Wall.

There is debate over whether some sites continued in occupation through this period (such as Cramond, where Holmes (2003, 154-5) argues the excavated evidence shows no clear break in occupation). It is also increasingly plausible that there may have been new foundations at this time. The legionary base at Carpow has long been seen as a Severan foundation, but reappraisal of both inscriptions and tiles from the site has been used to argue for suggested a Commodan foundation (RIB III, 3512-4; Warry 2006, 65-9). This would be, on current knowledge, a very isolated outpost, albeit one with good maritime connections, and if the interpretation is sustained raises questions about the nature of activity in Scotland at this time.

The sequences at the key sites of Cramond and Carpow, and the question of the end of Inveresk, need reappraisal as they are becoming critical to this period. A study of their pottery assemblages in the light of improved knowledge of the sequence on Hadrian's Wall at this date (from work at South Shields and Wallsend) would be very valuable.

3.5 The Antonine Wall

Reconstruction of the Antonine Wall at Callendar Park, reproduced courtesy of Falkirk Museum and M. J. Moore DA FSA Scot

The Antonine Wall has seen considerable interest in recent years, leading up to its inscription as a World Heritage site in 2008 (and see 4.2). A programme of geophysical survey has provided some additional information about forts and the military way, although much is still to be learnt. A study of the coarse ware pottery found along the Wall identified styles in use in North Africa, leading to the suggestion that troops from this area arrived on the Wall after the Mauretanian War (Swan 1999). An alternative historical sequence has been proposed for the construction and development of the Wall, but this is not fully reconcilable with an earlier proposal relating to the timetable for the addition of annexes to forts along it (Bailey 1994). Indeed, the timetable for both the building and abandonment of the Wall are subject to much debate (e.g. Breeze 2006a, 99-102).

The Antonine Wall Management Plan (Breeze 2007) identified the need for 'a research programme for the Antonine Wall within its international framework'. Such a detailed consideration lies outwith the scope of this Framework document, but it is hoped that some of the issues raised here will be of relevance to Wall studies, and that following on from this wider Roman Iron Age study, a more detailed research framework for the Wall will be created. Perhaps the key point to stress here is how many issues remain ripe for research.

The crucial date relating to the end of the Antonine Wall system is an inscription from Hadrian's Wall recording rebuilding in 158 (RIB 1389; Hodgson 2011).This indicates an intention to reoccupy Hadrian's Wall and abandon the Antonine Wall, and is supported by the continuing rebuilding programme on Hadrian's Wall through the 160s (Breeze and Dobson 2000, 131-3).

The latest dated coin from an archaeological context on the Antonine Wall is a worn coin of Lucilla from Old Kilpatrick, struck between 164 and 169 (Robertson 1978, Abdy 2002, 196, 211), though there are later chance finds. It is possible therefore to envisage a significant period when there was activity on both frontiers, with one being de-commissioned and the other repaired/rebuilt.

The decommissioning of the Antonine Wall involved the removal of the distance slabs from their stands and, it would appear, their burial in pits. Other inscriptions might have been dropped into wells, as at Bar Hill. Fort buildings were demolished and in some cases burnt; ramparts were slighted. There was, however, no attempt to flatten fort ramparts or the Wall itself, as its survival and visibility as an earthwork demonstrates. Reasons for the withdrawal remain the matter of debate.

Some of the detailed questions which remain unanswered about the Antonine Wall at this time include: (a) the location of the eastern terminus; (b) in places, the exact course of the Wall where no longer visible; (c) the purposes of the enclosures, expansions, and platforms attached to the rear of the rampart; (d) whether or not there were fortlets spaced 1 Roman mile apart all the way across from the Forth to the Clyde; (e) and if towers and/or a Wall-walk existed along the length of the Wall and (f) what were the social and environmental impacts of construction of the Wall. In addition, north of the Wall, and contemporary with it, there was a corridor of forts linked by a well- built road extending up to and beyond the River Tay. This would seem to be more than a superficial chain of outpost forts, and raises the question: just where was the boundary of the Roman province in Antonine times?

Publication of the excavations at Bearsden, Croy Hill, Falkirk, and Mumrills (see Table 4) would be extremely beneficial, as would analysis and publication of the geophysical survey results obtained for the World Heritage Site nomination process. Further analysis of the finds from excavated sites along the Wall is recommended, building on the work undertaken by Hartley (1972), Gillam (1970) and Swan (1999), for instance to study life on the frontier, compare the nature of finds from different types of site (e.g. primary c.f. secondary forts), and use their potential as a dating horizon of much wider relevance to Roman studies.

Fieldwork issues include the need for more work at Auchendavy to determine whether it or Bar Hill is likely to have been a 'primary' fort; to address the perennial question of the eastern terminus of the Wall; and whether there are further outpost forts or fortlets to the east (eg at Blackness) to strengthen the known 'screen' along the coast.

Antonine Wall with forts and fortlets © Crown Copyright Historic Scotland