Ribchester - Catterall: Roman Road
RIBCHESTER – LANCASTER ROMAN ROAD
11 & 12 AUGUST 2019
That the Romans were great road builders is an undisputed fact. Both on the Continent and in Britain, examples can be seen as surviving physical remains and arrow-straight lengths of modern tarmac overlying Roman routes. How Roman engineers laid out those routes has been, and continues to be, a subject of conjecture if not of dispute among many experts; some favouring the opinion that routes were mapped out over considerable distances between significant forts or settlements, whilst others argue that their engineers surveyed over more limited horizons using natural vantage points or temporary structures to take bearings, taking into account natural hazards such as bogs, and obstacles such as steep inclines.
A further point of discussion lies in, or rather around, roadside ditches; major roads generally had two on either side. Were they simply for drainage taking water from the neatly cambered agger, or for traffic control, separating military from civilian road users, horse-drawn from pedestrian, or did they have a more significant purpose? In the absence of any surviving Roman Road Builder’s Manual, no-one can claim to have a definitive answer. An emerging view potentially lends support to the idea that Roman engineers laid out roads over short – admittedly straight – sections and that the ditches, particularly the inner pair, were dug first in order to mark out the line, the spoil contributing to the build-up of the agger.
The roads were essential to the pacification of Britain following the initial conquest and to its later development as the Province of Britannia. Despite a number of more recent studies, the reference point for most investigators is Margary’s Roman Roads of Britain (Margary I D, 1955-7), in which were classified all the then-known or surmised roads in a numerical system which has remained as the most comprehensive gazetteer of Roman road since then.
THE ROMAN ROAD NETWORK
The Roman conquest of the island of Britain began in the south-east in AD 43, the legions over the next 20 years subduing tribes in the south-west, gradually establishing a de facto frontier on a line from the Humber to the Severn. Progress was temporarily halted by Boudicca’s rebellion in AD 60/61 and it wasn’t until the later 60’s that the North began to come under Roman control, with the Brigantes and the Parisii tribes becoming assimilated into the Empire in the early 70’s. The North-West remained a hostile, or at least unsettled territory during this period and even towards the end of the 70’s Roman control was not fully established; the Brigantes and the Selgovae of southern Scotland having to be subdued again in around AD 79, coinciding with the foundation of the major legionary forts at Chester and Lancaster. It’s likely however that these forts were built on or close to the sites of earlier turf and timber forts dating from around AD 71 or possibly earlier, since the fort at Ribchester and the outpost at Kirkham (and possibly Burscough) already existed at this time.
The construction of the Roman road network necessarily followed the progress of the conquest, the roads being built by the military for the purpose of moving troops and supplies between military stations. Therefore it’s likely that the Ribchester - Walton-le-Dale - Lancaster road was constructed sometime between AD 69 - AD 73 and the Ribchester - Catterall - Lancaster ‘link’ road being constructed later, possibly between AD 73 and AD 79.
THE RIBCHESTER – LANCASTER ROMAN ROAD
The route taken by a road from the Roman fort at Ribchester to that at Lancaster had been the subject of speculation and of serious research for close on two centuries. The prevailing view was that the road followed a fairly direct line NNW, over Longridge fell, passing either east or west of Beacon Fell and joining the S-N road near Galgate. The rationale for this was simply that such a direct route must have existed; there were place names along the line (Broadgate, Street, Street Bridge, Stang Yule (probably a misprint for Staney Gate) associated with Roman roads, and there were here and there isolated landscape features that hinted at the possibility of an agger. Despite the lack of any hard physical evidence this route was included in the 1846 First Edition Ordnance Survey map as ‘supposed Roman road’ and was later enshrined in Margary’s 1957 Roman Road bible as Margary 704.
The public access to the Environment Agency’s LiDAR data was the key to disproving this supposition. Roman road researcher David Ratledge had used this technology to locate the route of a number of Roman roads, in some cases proving the OS maps to be incorrect. A significant LiDAR-based discovery was that the Walton-le-Dale to Lancaster road (Margary 70d) did not follow the direct route of the current A6 but at Cabus headed NNW towards Cockerham (in Roman times on the sea) before turning NNE at Ashton and then N just south of the Lancaster fort.
LiDAR imagery now led Ratledge to identify the Ribchester - Lancaster route as running through Longridge and Inglewhite to Catterall where it joined the S-N road. David was able to check out his discovery in the field by visiting accessible points on the route and looking for indications of an agger or cutting typical of Roman road engineers. Ian Milnes, a metal detectorist and associate of David's, using David's published LiDAR projections to identify potential detecting targets had, over several weeks, been detecting at a farm in Claughton near Bilsborrow and had realised that something significant lay under the surface of a particular field. Having gained the farmer's trust, Ian got agreement for Ratledge to visit the site and he, investigating by using a metal probe and small test-pits, was now convinced that the road had been located and suggested to colleagues in Wyre Archaeology that an excavation could put this beyond any doubt.
The detectorist sought and obtained permission from the farmer for a limited excavation once his crop had been harvested and before his winter crop sowing. Accordingly, after a brief site survey that revealed a promising 21 metre-wide scatter of small stones and pebbles across the length of the field, a two day window was proposed as a suitable opportunity to excavate.
The excavation by the Wyre Archaeology team took place over the two days 11 and 12 August 2019. The earlier site survey had identified an appropriate location clear of an overhead HT cable where it was planned to open two trenches at points where it was thought the inner boundary ditches might be located and, subsequently, open a trench across the presumed centre of the agger. Depending on progress a further trench might be opened outside the field in the grass verge bordering the metalled farm track where the track rose to pass over the agger. In the event, having located and opened trenches to expose the ditches, these trenches were simply extended across the full width of the agger.
The field surface was thickly covered in stubble from the recent harvest. Under this stubble was found a distinct stone scatter some 21 metres wide running the entire length of the field corresponding to the line of the road as perceived in the LiDAR image. The topmost plough soil had a depth of between 100 and 150mm.
The two presumed inner boundary ditches were excavated to a depth of approximately 800mm but although in section there appeared to be a distinct fill they did not appear to conform precisely to the expected Roman v-shaped cut and it transpired that the eastern ditch had been truncated by a cut at its northern side to lay a ceramic field drain. On closer inspection it appeared that this had also compromised the eastern surface of the road. The western ditch also contained a semi-cylindrical feature at a depth of 75cm that could have been decayed organic matter – possibly a D-shaped wooden post however this could not be verified and it may be that this ditch had also been compromised by the laying of a drain.
On extending and joining up the 1m-wide ditch trenches, the surviving surface of the road was revealed to be just over 8m wide and comprised of small stones, probably pebbles taken from the nearby River Brock and approximately 20mm -25mm in size. The surface had an obvious camber, rising some 100mm from the edges to the centre. This surface layer was approximately 150mm in depth, although it was apparent that the topmost metalling had been disturbed and dispersed by ploughing over previous centuries. At the centre of the agger a 1m x1m trench was opened and excavated down to what was presumed to be the natural surface in order to reveal the underlying structure of the road.
Beneath the surface layer was a further layer of pebbles of varying sizes from 25mm to 150mm. These in turn were laid on a bed of larger river stones of approximately 200mm in size. Since there was no apparent dark humus layer indicating decayed turf it appeared that this foundation layer had been laid directly on the natural clay which was blue-grey in colour, at a depth of + 800mm beneath the topsoil.
At the conclusion of the excavation, as agreed with the landowner, then trench was closed and backfilled.
The excavation and surrounding area were subject to a thorough metal detecting survey and field walk but there were no significant finds.
The dig was a success in that it achieved the aims set out in the project plan. However in post excavation discussion there have emerged a number of valuable lessons. Firstly more time could have been taken to investigate the boundary ditches more thoroughly, particularly when evidence was found that they had been compromised. Extending the ditches parallel to the line of the road by another 1m may have offered more definite proof that they were the actual ditches and that they had been explored to their full depth. Similarly the 1m sondage at the central point of the agger could have been excavated to a slightly greater depth to satisfy the question of whether the clay surface encountered was indeed the natural. However, on balance, given the limited time slot and the very changeable and sometimes very unpleasant weather the outcome was rewarding. It is hoped that another opportunity will be forthcoming to revisit the site and excavate elsewhere along the line of the road.
That this is the location of the Roman Ribchester-Lancaster link road there can be little doubt. The excavation proved the existence of a road constructed in a method known to be Roman and its line conforms exactly to the route revealed by LiDAR imagery. In the total absence of any contradictory evidence it is well justified to classify this road as Margary 704aa.
EXCAVATION TEAM – WYRE ARCHAEOLOGY
Tom Anderson, Dave Berry, Chris Birkett, Chris Drabble, Mike Edwards, Brenda Evans, David Hampson, Andy Jackson, Darren Meadows, Simon Millward-Hopkins, David Ratledge, Steve Rice
1. Roman road ditches at Red Scar Industrial Estate Preston on Ribchester to Walton-le-Dale road. Google Earth
2. Roman Roads in Lancashire showing location of WA Excavation. D Ratledge
3. LiDAR image of route of Roman road north of River Brock crossing at Matshead, Claughton. D Ratledge
4. Excavation Site. D Ratledge/Roman Roads in Lancashire
5. Trench plan. D Ratledge/D Hampson
6. Eastern Ditch. D Hampson
7. Western Ditch. D Hampson
8. Road surface looking west. D Hampson
9. Drone photo showing road surface, side ditches and central sondage. C Drabble
10. Plan and profile of road surface. C Drabble
11. Section photo/drawing of road structure. C Drabble
Roman Roads in Britain. Vol II. Margary I D, 1957.
Lancashire's Roman Roads, a Lidar Reassessment. David Ratledge, Lancashire & Cheshire Antiquarian Society Transactions Volume 110, 2017.
Romans and Britons in North West England. Shotter D, 2004
REPORT PREPARED BY: D W Hampson & D Ratledge, 3rd November 2019