Archaeology Tuesdays – Aldwick, Barley

In early 1959, Jack Wilkerson, a farmer and amateur archaeologist in Barley, southeast of Royston, made a discovery on one his fields. The field’s name – Aldwick – is a clue that something ancient lies under the ground there: recorded since the time of Elizabeth 1 (1558-1603), it is from Old English old (’old’) and wic (‘habitation’). It lies on a gentle slope north of the village, west of Bakers Lane, on the north side of a shallow valley facing northeast towards the county boundary at Cumberton Bottom. Digging into darker circles in the field, Mr Wilkerson found that they were surface traces of infilled pits that contained animal bones and prehistoric pottery of Early Iron Age type (about 800-400 BC).

At this point, he contacted the University of Cambridge for advice. The Disney Professor of Archaeology, Grahame Clark (1907-1995), had just been elected President of the Prehistoric Society and arranged for a magnetometer survey of part of the field. It was a new, experimental technique that was first used archaeologically in 1956: no-one had previously tried it on a site with chalk bedrock. Although the results appear vague when compared with those we might expect to see today, the surveyor Martin Aitken (1922-2017) was pleased with them. They revealed a large, flattened horseshoe-shaped anomaly as well as groups of smaller potential features. A more detailed survey of the area around the horseshoe-shaped confirmed that the signal derived from something measuring about 13 m wide and 9 m deep.

Professor Clark then sent Mary Cra’ster (1928-2008) to excavate the site. She revealed 101 roughly circular pits and found that the horseshoe-shaped anomaly was caused by a buried ditch of the same shape. The ditch had a uniform fill and contained almost no finds, unlike the pits. Both ends were cut through earlier pits, and the ‘open’ end faced obliquely down the slope. Mrs Cra’ster thought that it was the drip-gully of a building but although postholes were found both inside and outside the area it enclosed, none could be made into a convincing roundhouse shape.

During the 1959 season, the archaeologists excavated 101 pits in an area 33.5 × 24.4 m (817.5 m2). In the following year, they found another 31, in 1961, a further 18 and in 1962, another two, making 152 in total. Aerial photographs show that this is just a small proportion of the total; they also indicate that the pits are grouped into more than a dozen clusters. Groups of pits like these are typical of Early Iron Age sites (including, locally, at Blackhorse Road in Letchworth Garden City and Jacks Hill in Graveley).

The pits at Aldwick vary greatly in size. The largest were a little over 3 m in diameter, while the smallest were only 0.75 m in diameter; their depths similarly varied between 1.4 and 0.15 m (remembering, of course that this was the depth cut into the chalk, not from the original ground level). Most had vertical sides and flat bases, although some were wider at the base than at the surface of the chalk (often described as bell-shaped) and a few had sides that sloped in towards the base. Sixteen pits were more irregular, and Mrs Cra’ster was unsure if they were deliberately left this way or if they were unfinished examples of the more regular types.

All the pits were deliberately backfilled, and none showed signs of silting. The material consisted of three types: pure chalk rubble, a mixture of chalk rubble and domestic rubbish, and pure domestic rubbish. It is unlikely that the pure chalk came from digging the pit it was found in: there would be little point in keeping it ready from backfilling. Instead, it perhaps came from a new pit being dug next to the one being filled in.

One of the largest pits contained a layer of ash in the bottom, evidently from a fire that had consumed material inside it. The ash contained cereal grains and other seeds, as well as a burnt plank, potsherds from a single, broken pot and a small iron sickle. Mrs Cra’ster suggested that it was an accidental spontaneous combustion of damp grain being stored in the pit, although it is difficult to account for the potsherds, as the pot they came from was already broken at the time of the fire. Perhaps it fell into the pit during the fire. On the other hand, it could have been the deliberate destruction of grain ruined by fungus or mice.

Why do we find so many pits on Early Iron Age sites? A hundred years ago, archaeologists interpreted them as houses (‘pit dwellings’) as they often contain domestic rubbish and traces of burning, which were thought to be hearths. Thanks to the work of Gerhard Bersu (1889-1964), a German archaeologist who fled Nazi persecution in the 1930s, who excavated at Little Woodbury (Wiltshire) in 1938-39, the idea of pit dwelling was discredited. His two trenches identified the postholes of a roundhouse, which he recognised as the main dwelling on the site, and numerous pits that he interpreted as being dug for grain storage.

During the 1960s, Collin Bowen (191-2011), P D Wood and Peter Reynolds (1939-2001) tested Bersu’s hypothesis. They found that so long as the bedrock is well-drained, the pits cut into it make excellent grain storage silos so long as the temperature inside them remains below 12° C and the contents are kept dry. Each pit needs to be filled to capacity for long-term storage to work, and the average pit will have contained more than a tonne of processed grain. This tells us a lot about the efficiency of agricultural production in the early first millennium BC. At the experimental farm at Butser (Hampshire), Peter Reynolds found that a single pit can remain viable for more than twenty years. The grain would form a protective skin where it was in contact with the bedrock, and some of the pits at Aldwick had evidence for it. Whether any pits were used for more than one season cannot be proven with existing archaeological data: it is possible that they were abandoned after just one year.

Archaeological thought and interpretations have moved on since the 1960s. We now know that not all pits were used for grain storage and we also know that those that were had an ‘afterlife’. Iron Age societies were very different from ours and people did not separate their religious beliefs from everyday activities. This distinction came about as recently as the eighteenth century, when the Enlightenment tried to make rational thought the basis of everything we do. Our modern attitudes, which seem so natural to us, are unusual in the broad sweep of history.

Taking this into consideration, we can see how the people at Aldwick would have seen their pits as connected with the realm of Andumnos, the underworld. Unlike the Classical underworld, which was a place of gloom and mists, Andumnos was a paradise of eternal youth and plenty. Putting grain underground was perhaps seen as a way of preserving its ‘youth’ and ensuring that food would be plentiful in the coming year. When a pit fell out of use, people would need to make offerings to the gods who had taken care of their produce. During the 1990s, archaeologist J D Hill showed how they would place special pieces of pot, bone and even human remains into disused pits. They also placed rubbish that had been left out on open middens. This explains why the pits at Aldwick did not just silt up but were deliberately backfilled as soon as they were no longer needed. It also explains why sherds from the same pit could be found in different pits. Perhaps these vessels had developed a special significance while they were in use, making them valuable gifts to the underworld deities. A dog skeleton found in one of the pits was probably not simple ‘rubbish’, but the burial of a valued (non-human) member of the community, in the same way as an infant skeleton was placed in a couple of the pits.

Making a pit was hard work. If several people worked on one at the same time, it might take half a day to make a typical cylindrical pit. Bell-shaped pits are more difficult to dig, as the overhang carries a risk of collapse, so perhaps experienced pit-diggers worked on these, passing the skills on to younger workers. As we have seen the evidence of filling suggests that in some cases, the diggers made a pile of the chalk they removed or, perhaps, shovelled it straight into a nearby empty pit.

A large ‘working hollow’ on the west of the site was partly examined in 1961. The term covers a wide variety of functions. Some were where people mixed clay, dung and straw to make daub for house walls. Others were perhaps the bases of clamp kilns, effectively large turf-covered sunken bonfires for firing pottery. Some may have been areas where livestock gathered regularly and wore away the ground surface. On one edge of the hollow were burnt bones from a child aged 8 to 9 years old. As with the pits, the bones were perhaps offerings to the ruler of the underworld or aimed to send the child’s spirit to a happy afterlife in paradise..

As well as pits and a ‘working hollow’, there were groups of postholes. One group of four excavated in 1959 was a typical ‘four-poster’ structure, often thought to be above-ground granaries. These may have for grain that would be used in the near future rather than for long-term (over-winter) storage. The others, around the horseshoe-shaped ditch, do not make a pattern that suggests a building. Some of them can be joined to make straight lines, which may mean that they show the position of fences, but there are too few to be certain.
The Iron Age farm or hamlet must have been successful. Aerial photographs show that the pits spread across much of the field, with associated ditches perhaps defining areas that were farmed. There may even have been earlier activity on the site, as metal detectorists have found two broken fragments of a Middle Bronze Age (about 1550-1150 BC) rapier; one piece is the tip, the other from the middle of the shaft. Although found 7½ months apart, these two pieces were probably from the same weapon. The break may have been deliberate: North Hertfordshire Museum has on display a Middle Bronze Age sword from St Ippollitts broken into three pieces before being thrown into a pond.

The accompanying aerial photograph shows the site, with its huge density of pits in the centre and north of the field, with the ‘working hollows’ down to the south and one to the west. On the south-eastern side of the site are some ditches that may show where contemporary field were located. A pair of ditches widely separated runs from the south of the site towards the north-northwest. If they are part of a single feature, they might be part of a droveway for livestock. It is interesting to see that almost all the pits on the site lie to its northeast, while all the ‘working hollows’ lie to the southwest, a good indication that the ditches were in use at the same time as the rest of the site.

One mystery remains. How did the medieval peasants who named the field know that it was the site of an ‘old habitation’? Perhaps we underestimate how much people in the past recognised the traces of ancient pottery and metalwork as belonging to people even further back in time.

Written by Keith Fitzpatrick-Matthews