Danebury, Butser and the interpretation of Iron Age hillforts

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1 Key study Danebury, Butser and the interpretation of Iron Age hillforts The Iron Age hillforts of Wessex provide a good example of the way different questions, emphasis upon different evidence and different analogies can lead archaeologists to quite different conclusions. Early studies of hillforts often began with classical sources and looked for evidence to support those historical accounts. Caesar had described chiefs and the warlike nature of the Celts. Evidence of violence at sites such as Hod Hill seemed to confirm this. Excavation of several hillforts has revealed military features including evidence of timber or stone facings to the massive ramparts and caches of slingshots. These might be expected at the strongholds of powerful chiefs. More recently a variety of different models and analogies have been used to understand hillforts and this has led to radically different interpretations of Iron Age society and settlements. Cunliffe s (1985) excavations at Danebury (p. 184) initially seemed to support the political-military interpretation. In addition to large numbers of roundhouses within the defences, the site appeared to have a massive storage capacity. This might indicate foodstuffs being stockpiled by a chief for redistribution or exchange. Metal objects included bronze harness fittings, iron spearheads, cauldron hooks and sword-like currency bars. These and occasional finds of exotic material such as amber bolstered the idea that it was a high-status site. Other evidence pointed to craft production of textiles and the consumption of large numbers of animals. Cunliffe used classical and early medieval analogies to interpret Danebury as the seat of a chief (p. 427) with specialists and possibly a warrior aristocracy. He drew analogies from geographic models of settlement patterns (p. 245) to interpret Danebury as a central place. He noted that a wide distribution of hillforts gave way to fewer, larger hillforts later in the first millennium BC. He interpreted this as representing a wider scale of social organisation with the development of a tribal chiefdom dominating a large territory. Structures The hillfort certainly had a huge storage capacity. This took two forms. Among 18,000 postholes, hundreds of four- and six-post structures were identified and there were also 5000 pits. Both features are common on Iron Age sites but rarely in such numbers. Ethnographic analogy (p. 180) suggested that the four- and six-posters might have been raised granaries. To test this idea, several full-scale models of different structures were built at Butser Ancient Farm. This innovative open-air laboratory had already been one of the first places to experiment with constructs based on excavation floorplans. Apart from the postholes, another clue was provided by traces of wattle and daub panels which might have been the walls of these structures. The Butser model made sense as it kept grain out of reach of rats and allowed air to circulate to prevent damp.

2 Experimental roundhouses were also constructed at Butser. The walls, beams and roof itself drew on knowledge of Iron Age carpentry and engineering. These constructs enabled the exploration of ideas about the roof pitch, light, efficiency of fires and whether a smoke hole is needed. Reynolds (1989) demonstrated that a smoke hole would have turned the house into a furnace. Instead smoke filtered through the thatch where it may have also contributed to waterproofing and reduced vermin. Butser also answered questions about how long a roundhouse might last and the amount of woodland needed to build and maintain it. The ancient farm also investigated Iron Age crop productivity and animal husbandry. Agriculture and storage pits Carbonised grain was recovered from the Danebury pits, while seeds and snails were recovered from soil samples by flotation and wet sieving. Analysis and interpretation of these finds revealed much about the farming economy. Microscopic examination of plant assemblages identified the main crops as einkorn and emmer wheat, but also found over forty types of weed. This suggested that wheat was brought to Danebury unprocessed since weeds had come too and also that wheat came from a wide area. This is because plants are good indicators of local environments and because we know the conditions that various species can tolerate. Weeds are particular to certain soil types and locations such as wet lowland valleys or higher chalk pastures. From the types of weed present, archaeologists were able to infer the soil conditions in which the crops were grown before being brought into the hillfort. This information meant that the catchment area of Danebury in terms of agriculture was more clearly understood and future research could be focused on understanding the nature of the links between Danebury and surrounding farming settlements. Assemblages also contained much chaff, which historical and experimental analogies showed to be a by-product of processing (p. 122). Many of the pits cut into the solid chalk were bell-shaped. They were 1m wide and up to 2m deep with a grain capacity of over 2 tonnes each. Initially it was thought that the pits had been sealed and

3 covered with a basketwork lid so that their contents would last over the winter. How they did this without rotting was unclear. To investigate, the archaeo-botanist Hillson conducted a microexcavation in his lab of a sample of carbonised grain from a pit. As he removed and counted the seeds layer by layer, he discovered that there were more germinated seeds at the bottom, next to the chalk. Reynolds (1979) tested Hillson s findings at Butser by digging a replica 1.5m pit and filling it with grain. Instruments were inserted to measure humidity, temperature and gas exchange. The pit was sealed with an airtight layer of clay. The results were impressive. The grain around the edges, especially where it was in contact with the chalk, began to germinate and produced shoots. This gradually used up the available oxygen and produced carbon dioxide, creating an anaerobic environment and germination ceased. While the seal remained intact, the grain lay dormant and survived the winter in good condition. When the pit was opened, most of the grain could be used except for that around the edges, which was full of mould and fungi. If the pit was to be used again, this waste had to be disposed of. Reynolds suggested that it was burnt in the pit, which accounted for the carbonised grain at the bottom. It is likely that the grain was taken out in one go, perhaps for sowing or trading, rather than used as a larder for food. The zones where grain would germinate and spoil are shown in the below figure. Ladders and baskets or buckets would be needed to empty a pit of this depth. Excavation on contemporary sites suggested that pits were usually backfilled to preserve their narrow entrances from collapse and not present a hazard. It was easier to re-dig them than start a new pit. Curiously this seems to have been rare at Danebury. A magnetometer survey of the nearby hillfort at Woolbury revealed very few storage pits. Cunliffe used this finding to support his idea that Danebury was a higher status site with a redistributive function. Alternative interpretations

4 Not all large hillforts in Wessex appear to have had the same function. Maiden Castle had been seen as the archetypal military fort by early excavators and there was evidence that it may have been defended unsuccessfully against the Romans. However, military use in such an emergency may have been atypical. Sharples (1991) found a more confusing picture. At times defences were built up, at others they were neglected as much of the hillfort was abandoned for long periods. Like Danebury there was massive storage capacity, first with four-posters and later with pits. Like Danebury there was little difference in size or artefacts between the individual huts massed inside its massive earthworks. The only signs of an organising power were the ramparts and the reorganisation of houses into rows during later phases. In many respects it was a giant farming village rather than a town. Outside there were few traces of the sort of farms which surround Danebury. This suggests that social organisation might have been different at the two sites. Hill (1996), in a series of attacks on Cunliffe s view of the Iron Age, undertook statistical analysis of the ratios of finds per cubic metre of soil excavated on a range of Iron Age sites. While Danebury produced more finds of loom weights, spindle whorls, ornaments and metal horse fittings than smaller sites, more soil was trowelled to produce them than on other sites. Comparison of the ratio of finds to volume of spoil suggested that Danebury was unexceptional in its density of craft tools and fine goods. Several farmsteads such as Winnall Down produced higher densities of many finds and more evidence of iron working. These sites also had their own storage and similar sheep assemblages to Danebury. Hill also pointed out that the densely packed settlements on rich farmland in the Thames Valley (within a day s ride of Danebury) were undefended. This was hardly likely if hillforts were bases for raiding warbands. Hill used this kind of data to argue for a less hierarchical and warlike Iron Age. Collis (1996) work provides a further insight. He sets hillforts into a tradition of special hilltop enclosures in southern England stretching back to the early Neolithic. Many hillforts overlie earlier monuments and Danebury in particular has a large number of ritual burials and other deposits in its storage pits. Hill also discovered that just as most round houses and enclosures faced east or south east, most hillforts opened east or west regardless of defensive considerations (p. 276). Hill did not suggest that they were never used for defence and never occupied by a powerful leader, just that those may not have been their sole or principal functions. Ritual and seasonal gatherings may also have been important.

5 Recent research The massive pottery and faunal assemblages at Danebury continue to provide material for researchers using new techniques. Recent lipid analysis by Copley (2005) showed that many storage jars had held milk. The age profile of cattle and sheep supported the idea that dairying was important at Danebury. Stevens (2013) compared isotopic (p. 133) signatures in the bones of animals at Danebury with those from other contemporary settlements in the area. It was anticipated that smaller settlements would have distinctive signatures of δ 13 C and δ 15 N, reflecting a limited environmental range in a small territory. However, there was considerable variation within each settlement. This suggests that either animals were moving to graze a range of environments, possibly on an annual cycle, or that fodder was being brought in from across a wide area. Either way it suggests a complex pattern of animal husbandry and possibly of land rights. Like Cunliffe, Stevens (2013) drew an analogy from medieval Irish models of clientage to help explain how this might work. Orientation of roundhouses

6 Orientation of hill forts Further reading K. Schick and N. Toth (1993) Making the Silent Stones Speak (London: Weidenfeld and Nicolson). This is a fantastic and well-illustrated exploration of taphonomic processes and the use of observation and experiments to understand lower Palaeolithic sites in Africa. L. Binford (1983) In Pursuit of the Past (New York: Thames and Hudson). This is a challenging read but is packed with ideas and arguments about the nature of the archaeological record and the use of ethnographic analogs in particular.