Sutton Common: The Excavation of an Iron Age Marsh-fort, edited by ROBERT VAN DE NOORT, HENRY CHAPMAN AND JOHN COLLIS
This book presents an extremely rare type of project in modern archaeology, the stripping, mapping and sampling of an entire late prehistoric defended site. The results of this exercise raise significant questions about our understanding of Iron Age chronology, the role of defended sites in the wider landscape, archaeological methodology and site preservation.
The site at Sutton Common, in South Yorkshire, consists of two multivallate enclosures located on a pair of sand islands in a small floodplain, separated by a relic paleochannel. The site is famous because of the investigations by C.E. Whiting between 1933 and 1935 that discovered waterlogged remains which led to the site being designated a Scheduled Monument. That was not enough to protect the sites however, as in 1980 all of the larger enclosure and part of the smaller one were bulldozed before the work could be stopped. That event destroyed the majority of any stratigraphy in the interior and another disaster occurred in 1982 when the Ministry of Agriculture established a drainage scheme that lowered the water levels by 2m, which investigations between 1987 and 1996 demonstrated were causing the slow death of the waterlogged archaeological remains.
Because of this threat Sutton Common was chosen as a Beacon Site, a model for cooperation between English Heritage and nature conservation organisations. In 1997 the area was purchased by the Carstairs Countryside Trust, irrigation channels were blocked and water levels were monitored. Between 1998 and 2003 English Heritage funded a £470,000 excavation of 20,600m2 of the larger enclosure, using a labour force of two Universities and two local archaeological societies. A lot of effort was used to involve the local community and local schools were introduced to the vagaries of archaeological preservation by burying everyday items and excavating them six months later.
The results have been mixed. The site is safe from further drainage and ploughing but GIS modelling of the water table using a grid of piezometers demonstrated that the desiccation of virtually all the waterlogged deposits has not been halted and cannot be, because of the previous lowering of the water table over the wider floodplain. The detailed information gathered on the preservation of the waterlogged remains provides a measurable benchmark against which the ongoing destruction of the next few years can be measured. The publication of this work provides a well-recorded example of the ongoing landscape-scale destruction of waterlogged archaeological deposits in the UK. As such it should provide a clarion call to the archaeological community to urgently protect these most informative parts of the archaeological record. Climate change and the lucrative lure of arable farming are likely to increase the rate of loss in the coming decades, a problem that will affect most European countries.
For sites that cannot be protected from such destruction, rescue excavation is one possible solution and Sutton Common provides an interesting case study for such an approach. All of the interior of the larger enclosure and a large proportion its defences were stripped and planned and 10% of the features were excavated. This has resolved the enigmatic character of the site, although the role of the smaller enclosure, here curtly dismissed as an elaborate entrance to the larger enclosure, remains open to question. The lack of significant excavation on the smaller enclosure is probably the main drawback of the research, as its relationship to its larger neighbour could be crucial, as is known to be the case with neighbouring Pā sites in New Zealand (eg, Armit in PPS 73, 2007).
Activity on the larger island began in the early Bronze Age with evidence of a single burial of pyre debris and the truncated remains of segmented ditch features that may also have been mortuary enclosures. Pollen evidence from the palaeochannel suggests that the first significant local clearance of the dryland woodland took place at this time but that it was short-lived with a period of regeneration before more clearance in the later Bronze Age and a marked decrease in woodland cover in the middle Iron Age, with grassland predominating over arable in the neighbouring dryland.
In the Iron Age the larger (c. 200m by 100m) island was fortified with a box rampart, an inner ditch, a palisaded ditch and an outer bank. Entrances existed on two sides defended by wooden gatehouses and reached by causeways across the surrounding wetland marked out by avenues of stakes, the western route reaching the dryland via one end of the smaller enclosure.
The interior of the enclosure produced the surprises. An almost total dearth of finds, matched by an absence of anthropogenic markers in the palaeoenvironmental record, suggested that the interior was never settled. Aside from a somewhat dubious hut, a few storage pits and a well, the interior was dominated by 150 four poster granaries in rows of up to eight structures scattered across three possible zones. Elements of ritual deposition were recorded that will be familiar from many other sites of this period, including the deposition of pottery, quern fragments and two, possibly defleshed, human skulls in a ditch terminal by the eastern gateway. The discovery of charred grain in the post holes of 24 of the granaries can also find many parallels but careful excavation and analysis at Sutton Common has proved that the grain was deposited as deliberate acts before the posts were erected rather than as a result of a granary fire or litter entering a void after the post decayed.
The chronology of the site is also very interesting. Because some large oak timbers were still clinging on to survival in the eastern gateway, tree-ring dating was successful in providing a felling date of 372 BC for a tree that provided 14 of the timbers in that structure. Another timber from the same area was from a tree felled ten years later, although sadly we will never know which part was being built then because the identifying label fell off the timber. Because of the absence of any evidence for rebuilding it seems logical that the box rampart and possibly all the banks and ditches were created at that time. The use of Bayesian statistics on a series of radiocarbon dates from one of the ditches suggests that all the defences were created by 350 BC and that the ditches had completely filled up by 200 BC at the latest.
At some point in the 4th to 2nd centuries BC the use of the larger enclosure changed from a defended grain store to an undefended mortuary area. The evidence for this was slight and it is a credit to the excavation team that it was detected. A series of twelve geometric enclosures, c.3m by 6m in size, were defined by steep sided ditches, within which pyre debris was scattered. The ephemeral nature of such evidence may help to explain the general lack of evidence for the disposal of human remains in the later prehistoric period.
The scientific dating of the Iron Age activity on the site provides evidence that quite grand and elaborate sites with multivallate defences may have been created over a very short space of time. In the case of Sutton Common this was 22 years at the most, and the purpose of the site may have completely changed after only one or two generations. No doubt if more timbers had survived many additional discrete events would have been recognised and perhaps the time scales involved would have shrunk even further. The dendrochronological data from the Neolithic and Bronze Age alpine lake settlements and the recent application of Bayesian statistics to stratified radiocarbon dates from long barrows and causewayed enclosures in the UK, have both illustrated the rapid creation and abandonment of prehistoric structures. The Sutton Common evidence suggests that a similar prognosis can be advanced for some Iron Age defended sites where traditionally the precision of dating evidence has been very poor.
Frustratingly for archaeologists this ongoing realisation of the short lived nature of structures and human activity in general, means that the extreme paucity of evidence for any particular period in prehistory will become increasingly apparent. Thankfully, for most sites the dating evidence is so woeful that we can still pretend that they covered a 200-400 year period rather than a 20-40 year one, ensuring that meaningless period distribution maps can still be produced in support of dubious theories about how communities interacted on a landscape scale. At least if all the wet sites dry out, that awkward tree-ring evidence will disappear with them, leaving us free to hypothesise grandly in the vacuum of ignorance.
So what are the grand theories about Sutton Common? The authors identify it as a new type of monument—the marsh-fort. These are defined by their defensive morphology and their location in lowland wetland environments, often situated on natural small hills reached by causeways. A total of 15 other marsh-forts are proposed, 12 in East Anglia and Lincolnshire and single examples in Wales, Shropshire and Somerset. Most of these have had very little research carried out on them and have seemed to be relatively empty, just as Sutton Common did before the complete plan of the interior was revealed. The small post features inside Sutton Common were not detected on geophysical survey, which provides another reminder of the inherent caution required in interpreting such evidence. The case for the new monument type seems quite convincing and offers an interesting contrast to the more obvious Iron Age hillforts. More research on the other sites is required to prove the case however.
For the detailed interpretation of Sutton Common two possibilities are advanced in the publication as though they are mutually exclusive. The functionalist interpretation is briefly presented with thinly disguised contempt. After all, how could any self-respecting modern archaeologist believe that a multivallate site with a box rampart, strong gateways, surrounded by a wetland that was only easily crossed by causeways, could have had any kind of meaningful defensive purpose? That sort of person would no doubt also believe that that the 150 granaries were all used to store grain, probably by some sort of local elite with authority over the surrounding landscape and that the short lived occupation could be a product of a shift in the balance of power.
The favoured processual interpretation concentrates on the ritual deposition (mentioned above), which is the key to everything. Once the reader understands this it all becomes clear. The existence of some causeways across the inner ditch mean that potential attackers could have strolled in at will and, of course, many of the granaries were never used to store grain. Instead all these physical remains were largely just a display, a theatrical performance, undertaken for reasons of social reproduction or the reinforcement of local social identities. The multivallation merely re-emphasised the symbolic nature of enclosure, defining and redefining the opposition between the internal cosmos and external chaos. Its obvious when you think about it.
As for that local elite, of course they never existed. Instead the creation of the defences and the granaries was a communal effort, perhaps steered by a transitory leader or peripatetic architect. Im not sure, but I think that last bit might have been from the Constitutional Peasants sketch in Monty Python and the Holy Grail. It doesnt really matter if you are a fan of this sort of stuff or not, because the book credibly fulfils the essential role of a good archaeological publication, presenting all the significant information in an easily understandable, well illustrated way, thus allowing the reader to make their own interpretation.
This publication provides the results of a very significant project in a clear and concise way while also incorporating a wealth of specialist studies that are well integrated into the main text and not left as unread appendices or confined to the oblivion of inclusion on an accompanying CD/DVD. In terms of methodology, it provides a very rare example of an extensive research excavation, that compares well to similar large scale projects undertaken through the planning system. It is a key site for the Iron Age period, defining a new monument category, raising questions about our perceptions of chronology, helping to solve the riddle of what happened to the dead, and ably characterising the role of an enormous defended granary within its landscape, or taskscape I should say. The monitoring work is a good case study of techniques and the depressing results of that work should be a spur to prick the archaeological community into doing something to protect other waterlogged archaeological sites and landscapes before those most precious and informative parts of the resource are lost forever. For those interested in the Iron Age or wetland archaeology this book is well worth the money.
Review submitted: May 2008
The views expressed in this review are not necessarily those of the Society or the Reviews Editor.
|The Prehistoric Society Home Page|