Late in January 2023, Keeley Sparrow, a resident of Holwell and regular visitor to the museum, wrote to say that she had spotted some cropmarks while using Google Earth. A quick check with Heritage Gateway, an online portal to databases covering the historic environment, revealed that they have not previously been recognised as such. Intrigued, I had a look at Google Earth and Lidar data to see if I could spot any further details. It soon became apparent that Keeley had discovered several hitherto unknown archaeological sites. By examining Google Earth views of different dates (available as Historic Imagery through the desktop app), I was able to build up reasonably detailed views of the three areas she’s drawn my attention to.

Part of Holwell and neighbouring Ickleford is covered in cropmarks of ice wedges, formed during the Devensian glaciation (the last part of the Pleistocene Ice Age, about 115,000 to 11,700 years ago). They typically outline interconnected polygons that superficially resemble chaotic field systems. The wedges are a result of cracks forming in the ground during very cold winters that fill with water in the summer; they freeze again, and the ice makes the crack larger. Eventually, the cracks filled with soil washed into them, which show as cropmarks in the same way as buried ditches. Enhancing the images using graphics software brought out subtle details that allowed me to separate cropmarks of likely archaeological and geological origin. This problem affected the site Keeley had discovered to the north of the modern village.

The first site lies to the south of the village. Keely wrote that ‘there appear to be some track lines which head North to South from the direction of the old landfill site… but which also branch off to the NW in the direction of the older part of the village’. She attached photographs showing these parallel ditches running north to south. There are three to the south and two to the north; the westernmost of the three at the southern end of the group turns to a northwesterly bearing about halfway across the field after it and its neighbour curve slightly.

The easternmost and central ditches coincide with the edges of a very slight bank visible on Lidar. As we shall see, this is significant and ties the feature into the wider landscape. However, the westernmost and southern part of the central ditches resemble a feature discovered at St Ippollitts in 2015. This was an Iron Age monument known as a banjo enclosure, a type originating about 500 BC and continuing into the first century AD. They were probably high status farmsteads and are often associated with coaxial (rectilinear) field systems; they are often later in date than these fields and inserted into them. We know of other Iron Age sites around Holwell, including at the former quarry to the southeast of the museum and on the edge of Pirton to the southwest. If the cropmarks do represent a banjo enclosure, it sits in a landscape where contemporary remains are abundant.

Even more intriguingly, the Lidar plot shows that the bank extends north of Holwell Road into the second area that Keeley highlighted. This is the area made very complex by ice wedge polygons, but it is still possible to detect ditches flanking the bank. Intriguingly, there are also cropmarks of reverse S-shaped ridge-and-furrow running over the top of the bank. As this is the shape of strips in medieval open fields, created by ox teams pulling the plough having to turn through a semicircle at either end, these cropmarks show that the bank they partly overlie cannot be any later in date than the Middle Ages. The bank could conceivably be much earlier, perhaps even contemporary with the banjo enclosure south of the village.

When we look at the wider landscape on Lidar, we can see that this very slight bank is part of an extensive system. They continue across much of the Bedfordshire lowlands and into North Hertfordshire north of the Chiltern scarp. In some places they coincide with modern field boundaries, but in others, such as the Pirton-Holwell-Ickleford area, they often do not. Even where present-day boundaries follow them, there are others that do not follow the grain of the current field systems. It looks as if at least some of them are part of a more ancient landscape, which the evidence from Holwell suggests is pre-medieval. It could well be traces of the sort of Iron Age coaxial field systems associated with banjo enclosures.

According to the Historic Environment Record, the field north of Holwell contains two ring ditches (usually the remains of a Bronze Age burial mound or round barrow) and ‘a complex of cropmarks here, apparently of enclosures but possibly geological’. My analysis indicates that most of the cropmarks are indeed geological, but that they are overlain by enclosures with straight boundaries. These do not appear to be part of the coaxial layout, but nor do they impinge on it. One ditch to the west runs at right angles to and crosses the denuded bank of the larger field system, but this could be part of it. It is also possible that the enclosures to the east are contemporary with it and belong to a settlement that developed within this organised landscape. If they are settlement enclosures, they are more likely to be Roman than Iron Age in date, as Iron Age settlements generally have curving boundaries.

Keeley’s third discovery lies to the southwest of the village. It consists of a very regular rectangle 38 by 63 m in size, with a subdivision cutting off the southern third. In the southwestern corner is a disused quarry. I initially suspected that the two features are related. The pit appears on the 1899 OS map as ‘Gravel Pit’ with an ‘Old Gravel Pit’ to its south, suggesting that it was in use in the 1890s. Its western and southern edges seem to match up with the edges of the enclosure. However, a thinner ditch on the same alignment extends both the northern and southern edges of this enclosure.

They are all on the same alignment as the ridges of the coaxial field system visible on Lidar, although they are not themselves visible as earthworks. The regularity of the rectangular feature suggests that it is either Roman or from the past two centuries. As it aligns perfectly with the earlier field system, it is likely to be Roman. It is plausibly an enclosure that contained a small villa of the type sometimes disparagingly called a ‘cottage house’. It would easily contain a building of the same dimensions as that excavated on the line of the Little Wymondley Bypass in 1991, 14.5 by 6.7 m. To put this into perspective, the Little Wymondly ‘cottage house’ is the same size as a large detached inter-war three- or four-bedroomed house: calling it a ‘cottage’ gives the wrong impression of small, cramped accommodation rather than a substantial family home!
This likely villa is only two or three hundred metres southwest from the possible banjo enclosure. Is it possible that after the Iron Age site fell out of use, the local landowning family that had lived there set themselves up in a new home nearby? In some cases – such as the Lockleys villa in Welwyn or the Park Street villa near St Albans – the late Roman villa sat on exactly the same site as the earlier roundhouse. In other cases, the location of the house moved. It may be significant that neither Lockleys nor Park Street are in banjo enclosures, while the banjo enclosure at St Ippollitts did not contain a later villa. Indeed, although about 250 banjo enclosures are known in Britain, none seems to be replaced by a Roman villa. Why should this be the case?

Barry Cunliffe has argued that banjo enclosures originated as large holding pens for livestock and later gained a ritual function, with evidence for feasting. This is contradicted by most excavated examples, which have found storage pits and houses inside them. Some contain evidence for metalworking and many have cooked animal bone and high quality pottery in their ditches. The ditches were often inside the banks, making it unlikely that they were defensive. In contrast to Cunliffe, Mark Corney suggested that they were ‘centres of power’ in the Middle and Late Iron Age. In other words, they were farms belonging to local chieftains and their families. The later Roman villas had the same function: they were the homes of wealthy landowners and government officials.

Perhaps what Keeley has discovered is evidence for a shifting pattern of high status dwellings around Holwell. Would it be going too far to suggest that the medieval manor originated in the estate controlled by their owners? Archaeology can only reveal the physical remains of the past, not the legal issues of land ownership and tenure, which we can try to infer from them. Trying to make these inferences is well worth the attempt as it helps us to understand what life was like for people in the past.

Written by Keith Fitzpatrick-Matthews

A large field in the south of Pirton, known as The Bury, was once the site of a medieval castle. Its earthworks enclose the parish church as well as some private houses and the mound of Toot Hill. The mound stands some 6.7 m high and is about 100 m in diameter; a ditch about 2.5 m deep surrounds it. The first record of its name is from the Enclosure Award of 1818, but it is a commonly found name (sometimes spelt Tuthill, as at Therfield) in which toot has the meaning ‘look-out, peep, be prominent, stand out’.

A teacher carried out an excavation with boys from the local school in 1935 on top of Toot Hill. The medieval ceramics expert Paul Blinkhorn examined the pottery, which is now in North Hertfordshire Museum’s store, in the 2000s. He found that most of it dates from the twelfth to fourteenth centuries, with some earlier material. Only one sherd of the fifteenth-century Late Medieval Transitional Ware that is found across the rest of the village is present, showing that use of Toot Hill continued at a low level after 1400.

What was Toot Hill built for? It is a typical Norman castle earthwork known as a motte. The Bayeux Tapestry shows the Norman invaders hastily throwing one up at Hastings in October 1066, and such earth-and-timber castles were important to the military occupation of England and a means of suppressing any possible revolts. They remained popular until about 1200: the stone keeps that we tend to think of as typical castles were mostly a later development. The motte formed a base for a wooden tower, surrounded by a palisade at the top and a ditch (or moat) at the bottom. They were cheap but effective defences. Part of the moat had been infilled before Clutterbuck wrote his history in the 1810s. Hitchin Rural District Council began dumping rubbish there in 1957, until the curator of Hitchin Museum pointed out that it is protected as a Scheduled Ancient Monument.

Most mottes had a bailey attached to them. Toot Hill has two, both obscured by later activity in the village. Letchworth Museum’s Field Archaeology team carried out a survey on the earthworks in January and February 1988, covering about 4½ hectares. Before the survey, it was believed that the deep hollow that runs across the middle of The Bury was the outer line of the main bailey. It soon emerged that this was one of the main streets of the village, Lads Orchard Lane, closed some time between 1822 and 1867.

Instead, coprolite digging has obscured the bailey ditch, and the bank inside it thoroughly levelled. Its line is still traceable, though. At the northeastern end of The Bury, Blacksmiths Pond, at the east end of Little Green, follows the line of the ditch, with the reduced bank behind it. It turns to the west and the bank is visible in gardens up to the edge of the churchyard. Another bank begins north of this one just before the churchyard, suggesting that the entrance to the bailey lay here. The edge of the ditch is then visible inside the churchyard as a change in level.
Traces of a second bailey survive east of the motte. A short stretch of ditch runs west from the south side of Toot Hill toward Bury End and it probably joined a pond that once stood in Great Green. Another hollow running northwest from the north end of the moat was still a watercourse in the early nineteenth century.

When was the castle built in Pirton? There are no documents referring to it, so archaeology must be our main source of information. George Evans, then curator of Hitchin Museum, carried out an excavation at The Bury in 1955. He was misled into believing that the former Lads Orchard Lane was part of the defences and confused by the paucity of medieval material and the discovery of a Roman yard surface instead. The pottery from the unrecorded excavation on Toot Hill suggests that it was not built as part of the Norman Conquest in 1066, but dates from the next century. The so-called Anarchy (the civil war between King Stephen and the Empress Matilda between 1138 and 1153) saw the construction of large numbers of castles, which would be an appropriate context for its construction.

Why was the castle built here? This is a more difficult question to answer. We might have expected a castle somewhere like Hitchin, the largest centre of population in this area, but (so far as we know), there never was one there. Pirton is not on a major highway and was not in the Middle Ages. Other castles locally are in predominantly rural locations: Meppershall, Cainhoe, Great Wymondley and Anstey. Perhaps they were designed to control the northern scarp of the Chilterns and routes through it.

Written by Keith Fitzpatrick-Matthews