Dr Will Wyeth, Property Historian at English Heritage, previews the geophysical survey, funded by the Castle Studies Trust, in order to learn more about the landscapte around Warkworth castle.
Following the success of a survey of Warkworth Castle’s earthworks in late 2020 as part of a scheme of reinterpreting this most palatial castle (report forthcoming), we on the English Heritage Warkworth project team have sought to expand upon our understanding of the medieval complex by turning towards its immediate landscape. Although much of the medieval landscape is not in the care of the charity, which looks after over 400 historic properties and sites across England, the landscape has tangible and nuanced connections which the project wants to explore. The castle is among the most prominent features in this area (Figure 1); its location adjacent to the lowest crossing point of the River Coquet means that low, somewhat boggy ground extends across the area south-east of the castle as the river widens to its mouth by the coastal village of Amble.
The plan of Warkworth Castle comprises a fairly typical motte and bailey, with stone superstructures of varying date and scale, and whose earliest iterations date from the late 12th century. While the antiquity of the settlement of Warkworth – laid out upon the north-south ridge of raised ground within this loop of the Coquet – is not known for sure, what is apparent is that the castle respects and influences the configuration of burgage plots and the coastal road ultimately linking Newcastle-Upon-Tyne and Berwick-Upon-Tweed. A walk around Warkworth village proper shows there are several important places and features which both relate to and indeed enrich the castle story.
The church of St Lawrence, itself probably constructed on the site of an earlier medieval church, is located mere metres away from the late 14th-century fortified bridge (Figure 2) which spans the northern extent of the river’s loop. The identification as a ‘fortified bridge’ is perhaps misleading. Thought to have been completed around the time the Great Tower at Warkworth Castle was finished, the bridge may be better understood as a toll collection station, though its administrative and security characteristics are not necessarily contradictory.
To the north, the coastal road carries on towards Alnmouth and onto Alnwick. It is in relation the immediate south and west of the castle, however, to which the Castle Studies Trust generously agreed to fund a further season of geophysical survey. Fields here testify to a legacy of cultivation which may be medieval in origin; traces of ridge-and-furrow are apparent immediately south and south-west of the castle (Figure 3), as well as in an area of ground rising gently from the river terrace, west of the Great Tower, across the river proper (Figure 4).
This new geophysical survey targets a cluster of fields adjacent to a modern pedestrian route to the castle which may fossilise a medieval antecedent (Figure 5), which would substantiate theories about the architectural orientation of major elements of the southern curtain wall of the castle towards the south-west. It also looks to locate with confidence the position of a suspected medieval hunting park boundary and access gate, which are sporadically referred to in manorial documents associated with Warkworth Castle in the late medieval period, but whose origins may lie in the 12th-13th-century, or (when considering place-name evidence) earlier still. Currently the park boundary is probably represented by a linear bank (Figure 6) with a southern return going westwards.
One of the fields in question bears the name St John’s Close, which had previously been thought to indicate the presence of a chapel here. In fact, the name likely references the field’s ownership by the Knights Hospitallers in the late medieval period, of uncertain origin but attested in a 16th-century return. The field is depicted in an estate map (which for copyright purposes cannot be displayed here) at the corner of a hunting park.
It is hoped that by firmly establishing the location of the medieval park boundary, any trace of a parallel routeway to the castle from the south-west, as well as the located of a gate into the park, English Heritage will be able to better draw the connections between castle and landscape which are now acknowledged as central components of castle culture. In turn, this will allow the charity to tell a more informed and more nuanced story about Warkworth Castle and the people who lived, worked and died here and hereabouts in its long history.
In her new book Authority, Gender and Space in the Anglo-Norman World, 900-1200, Dr Katherine Weikert, Senior Lecturer in Early Medieval European History at the University of Winchester looks at how medieval manors reflected and shaped – and were shaped by – their occupants to express social authority. In this article she looks at the facinating if little known Motte d’Olivet.
High in the lush forest of Grimbosq, Normandy, the remains of the Motte d’Olivet sit atop a lofty spur overlooking the Orne River valley. About twenty-two kilometres to the south of Caen, it’s a site that would be familiar to many castle-lovers: a man-made earthen mound, atop which formerly stood a wooden tower, with baileys on either side of it. A deep ditch around the motte kept it spatially and physically separated from both baileys. The motte-and-baileys take up the cramped, flat space on the point of the v-shaped spur surrounded by steep drops and small rivers on both sides (one charmingly called Ruisseau de Coupe-Gorge: essentially, cut-throat creek). The tower on the motte overlooked the whole area, and when the brush and forest was cut down around it, as it was in the eleventh century, the viewshed would have been spectacular. The Motte d’Olivet has long been considered a seigneurial residence, but its location, and the history of the man who built it, suggest a far less lofty purpose.
The site was excavated by Joseph Decaëns and published in 1981, though lingering questions remain about the castle and its builder. The elusive Erneis Taissan built the motte in the 1040s-50s during a period of conflict with his older brother Raoul. The Taissons come to greater prominence in Normandy in the twelfth and thirteenth centuries along Raoul’s line; Ralph Taisson, for example, was King John’s seneschal in Normandy at the turn of the thirteenth century. But in this earlier period, the family is more difficult to uncover, and the remains of the Motte d’Olivet are some of the only physical presence we have of them from this time. Decaëns even described Raoul as ‘un personnage très important mais assez énigmatique’ (a very important, but very enigmatic person)!
Seeking evidence of the brothers and their history is an exercise of charters, patience and this castle. Decaëns ascribed the tension between the brothers to each receiving portions of their father’s lands after his death, and Norman charters indicate some expression of this frustration through the brothers’ conflicting patronage of local monasteries. For example, the elder Raoul founded the abbey at Fontenay (St-Étienne de Fontenay, on the Orne north of Grimbosq) in 1050, and its foundation charter, confirmed by William the Conqueror, lists properties Raoul gave to the abbey, all to the east of the Orne. Erneis – who patronised Fontenay but may have preferred the abbey at Fontenelle – held estates mostly to the west of Raoul’s. Grimbosq and Cesny(-Bois-Halbout) are but two of these, with his descendants’ title even named for them. The lines drawn between the properties of these two brothers run straight through the forest where Erneis built his Motte.
Regardless of the cause of the tension, the Motte is the most obvious indication of the brothers’ strife, which visibly plays out the Norman landscape. The Motte directly overlooks the boundaries and roads between Grimbosq – Erneis’ land – and Mutrécy – Raoul’s land – with a clear sightline to the valley to the north, and a ridge to its east leading to Mutrécy. With this in mind, alongside the size of the castle and particularly its distance and isolation from any settlement, the Motte looks less like a seigneurial castle and more like an outpost, a short-lived watchtower to keep an eye on one’s pesky brother. It’s deeply unlikely this motte was Erneis’ main residence, but instead a place for his men to watch the boundaries of his land.
The northern enclosure holds a large aisled building, possibly two-storeyed, and additional stone rooms or buildings which have been interpreted as a sort of a gatehouse providing access to the motte, and a small separate kitchen. The apsidal room was previously interpreted as a chapel but this has recently been rejected by me on varying grounds (including location, orientation and charter evidence), which further indicates this place as less an elite residence and more an outpost. However, the state of the physical remains makes it unclear how to interpret not only the décor but quite simply the form and use of these buildings. The north bailey would probably have housed Erneis when he was there. But if that was this bailey’s primary intention, it would have only occasionally seen habitation, and more frequently seen the men on the watch accessing the motte via the gatehouse. The intention of this castle wasn’t in residency, but in the duties it performed for Erneis, in the watching and waiting done by his men.
The castle’s activity would have been focused in the south bailey. The south enclosure, which held a stable and forge, would have hosted a number of people and animals, and alive with the sights, sounds and smells of a working yard – hot iron and manure, the hammer singing against the anvil. It would have been a site of activity at the castle, a place for the retinue who staffed this border outpost. Game pieces found in excavation mean men entertaining themselves, or perhaps simply passing the time, the way you’d play cards in an airport. As Susan Reynolds and many others have pointed out across the middle ages, military men of a sort gathered together to wait and watch would have probably had some training or practice to attend to themselves: we can envision the south enclosure for this.
Wace tells us that the sons of the two men, Robert fitzErneis and Raoul (II) Taisson, both died at Hastings fighting with Duke William, and the rift between their two families was only repaired at this point. Erneis and Raoul (I) were probably already deceased and, to wit, the Motte was no longer in use by the FitzErneis line. Neither the Motte d’Olivet nor the warring brothers have been further investigated since the site’s excavation in 1981, and new questions about the place and its people can bring different views about what was once considered an elite house. What’s left of the brothers’ rift is just the landscape of this ruined castle, a lonely enclosure in an isolated place, high above the flourishing green forest, a lesson reminding us that castles have much to say about all the people who were once there.
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The aim is to understand the chronology and geography of extreme weather events in the high medieval period, and the effects they wrought on archaeological features that led to the abandonment of the old castle built in c.1229 in favour of the new built 200m away in c.1277. The latest thinking is that it was a series of extraordinary storm surge events which pushed a series of storm driven gravel ridges across the River Nith.
The methodology to find this out is interdisciplinary, using scientific methods to enhance understanding of archaeological fieldwork. The fieldwork will involve the establishment of a series of transects across the site and surrounding landscape from which cores and samples will be extracted for sediment description, stratigraphic analysis, and Carbon 14 dating.
Depending on Covid restrictions, the aim is to start doing the work in May this year with the receipt of the final data in the autumn.
The production of an interpretative phased floor plan for Greasley Castle in Nottinghamshire. The castle, built in the 1340s, has an obscure history and the understanding of its architectural phasing is at best very cloudy. The site is now a working farm and a number of post-mediaeval structures have been conglomerated around the remains of what is suspected to be a fourteenth century courtyard house with projecting corner towers.
The survey will act as baseline research data for a site which has not previously received serious fieldwork or publication and provide a basis for further research but also for any future conservation needs.
Work on the project will start in the early summer when covid restrictions ease.
Laughton-en-le-Morthen, South Yorkshire
To provide professional illustration and reconstruction which will also be integrated into a co-authored academic article based on the two previous research projects carried out on the site by Dr Duncan Wright and funded by the Trust. A geophysical survey and then small-scale excavation which give a strong indication that the Normans had built a motte on the site of a high-status Saxon dwelling.
Part of the monies will be used to produce phase plans of Laughton during key stages of its development, and a small percentage will pay for a line drawing of the 11th century grave cover incorporated into the fabric of the nearby church. The aim will be to start the work as soon as possible.
Old Wick, Caithness
Dendrochronological assessment of timber at the Castle of Old Wick, Caithness thought to be one of the earliest stone castles in Scotland dating from the12th century and the period of Scandinavian ascendency. Current thinking though ascribes the date to the 14th century. Analysing these samples will hopefully provide an answer.
With no architectural features or physical “independent” evidence analysing the remains of a timber joist-end (in poor condition) in one of the joist ends remains the best chance of being able to find an answer.
The taking of the samples is likely to take place in September when conditions are still going to be favourable as the castle is situated next to the North Sea and the sample can only be found 8 metres above ground level.
Richmond, North Yorkshire
Co-funding a three-week excavation of Richmond Castle, one of the best preserved and least understood Norman castles in the UK. The aim is to understand better the remains of buildings and structures primarily along the eastern side of the bailey including near the 11th century Robin Hood tower and near Scolland’s Hall.
Subject to the scheduled monument consent being granted the excavation will take place in late July.
Geophysical survey to explore evidence for subsurface features in and around the field called St John’s Close in a field adjacent to the castle with the aim to establish the location and eastern extent of the castle’s deer park in the 16th century as well as its entrance way. It also hoped to find evidence of a routeway running parallel to the possible park boundary which could represent an early route to the castle’s gatehouse from the south-west.
The plan is to do complete the geophysical survey by the end of March.
To keep up to date with how these projects progress over the coming months you can:
Lead Archaeologist on the Druminnor Castle excavation, Dr Colin Shepherd, looks at the results of the ground penetrating radar (GPR) survey of the castle in funded by the Castle Studies Trust in 2019 and what that means for future work at the site.
As a consequence of the GPR geophysics, that were generously funded by the Castle Studies Trust, we have a number of new and potentially interesting anomalies to be investigated. Furthermore, the GPR research has also been instrumental in clarifying other aspects of previously excavated evidence. This has been made possible as, contrary to most instances, the geophysics at Druminnor have been incorporated into the ongoing investigation rather than simply as a precursor to excavation.
The GPR generated 286 ‘radargrams’ or sections across the site and much time and effort has gone into analyzing these. The radargrams were compared to actual excavated sections. This permitted the creation of a ‘key’ that has allowed us to extrapolate from the excavated sections to unexcavated parts of the site. As a result, we can, fairly comfortably, suggest a developmental plan of Druminnor spanning the 13th to 18th centuries (Figure 1).
The GPR has suggested the extent of a hardcore platform that appears to have supported the ‘Old Tower’. This was thought to have been the earliest part of the castle but without hard evidence. We hope to test the presumed limit of this platform as we extend our trench southwards from the well that sat within the tower. (As you will recall, the GPR alerted us to that remarkable feature that became a focus for our 2019 season.) The GPR suggests that there may be a revetment supporting the platform at that point. Also, any relationship between this platform and the mid 12th-century kiln will be important in attempting to date that platform and, by extension, the Old Tower itself.
The radargrams have also demonstrated the probable line of a terrace and sunken formal garden (red hachures on plan) and permits the excavated section of revetment and steps (shown in black) to be placed in its proper context. This garden probably dates to the 16th or 17th century, though exactly when is still debatable. The construction of the terrace removed all trace of the earlier (early to mid 15th century) ditch and so must post-date that. A late 17th-century Dutch pipe bowl found in the fill of a post hole associated with the steps suggests its removal at around that time or shortly thereafter. No trace of the terrace appears on the estate plans of c.1770.
The line of the defensive ditch has been shown by the radargrams to extend westwards from the excavated portion in Trench 11. This gives us an accurate alignment permitting its course to be drawn, even though the middle section was removed by the terrace. Where its return is at the western end of the site is still a mystery. The eastern arm was excavated in Trench 2 lying beneath the later (early 16th-century) lower courtyard. The 15th-century upper courtyard incorporated the tower with the surviving hall block (shown in blue). The courtyard’s west range can be estimated from remains found during the kiln excavation, but its eastern boundary was removed when the lower courtyard was added.
Finally, the GPR revealed the line of the outer enclosure wall as depicted on the estate plans. This was sampled in 2019 and the base of the wall found. The date of this feature is presently unknown and further work needs to be done to try to clarify that matter.
Sadly, work planned for 2020 included the extension of the ‘well trench’ in the car park to look for the possible revetment suggested by the GPR as well as opening a much bigger area across the outer enclosure wall, as located by GPR. This sits beneath a good metre and a half of later landscaping material (see picture, courtesy of Iain Ralston) and, for safety and archaeological reasons, demands a much larger trench. The keyhole sample trench indicates good survival and, it is hoped, evidence will be found to date the feature and to help explain when this became the northern boundary of the castle enclosure.
The excavated evidence together with the GPR results permit this developmental plan to be made and rough dates affixed. It is worth noting that, prior to our investigations, Druminnor was believed to have consisted solely of the surviving hall block with an attached tower at its western end. Everything not in blue on the plan, therefore, was formerly completely unknown.
Access in 2021 is still, sadly, in the laps of the Gods owing to Covid, but it is hoped that we will be able to get back on track later this year to look for more goodies!
Dr Peter Purton, FSA, Castle Studies Trust trustee and author of recent works on medieval sieges and medieval military engineers looks at his latest area of research, later medieval fortifications and the impact of the introduction of gunpowder.
Castle studies were once ruled (in England at least) by wealthy amateurs, mostly male (Ella Armitage a stand-out exception) and many with military backgrounds. Every aspect of a castle, for them, was determined by military thinking. The late twentieth century counter-attack turned this on its head, stressing the symbolic role of castle-building as expressions of status and power. Some people challenged any suggestion that changes were driven by the need to upgrade defensive capability; and the same argument has been applied when guns arrived on the scene.
Those keen to argue the superiority of the English can always point to the first adoption (in Europe – the Chinese were centuries ahead) of gunpowder, and its first use for war. It’s also true that the English were the first to adapt fortifications to use guns, from the mid-fourteenth century, a little ahead of the Low Countries followed by the French, all places affected by the devastating impact of the struggles we bundle up in the title of the Hundred Years war (1337-1453).
Were loops created for guns also symbolic? If you take account of the historical reality of the time, this argument surely evaporates in a puff of (gun)smoke. I’m working on a new history of changes in fortification in the age of gunpowder with Dr. Christof Krauskopf and we delivered a paper at the (virtual) Leeds IMC in July 2020 addressing this question. We can’t answer the question without knowing the context, and what the builder wanted. The first is usually evident, the second is irretrievable. Across southern England from the earliest days of the war there were frequent seaborne raids by the French and their allies that caused local devastation and serious embarrassment (and loss) to the English crown. People could not know when and where the next attack would come. The response was the preparation of defences designed to use guns (at the time, they were not powerful enough to harm stone walls) from East Anglia (the Cow Tower of Norwich, for example) to Devon (Hawley’s Fortalice at Dartmouth), usually adapting existing defences but often building anew. The royal ‘architect’ (an anachronistic shorthand) Henry Yevele was directly involved in the erection of the Westgate and the reconstruction of the city walls at Canterbury and at private castles in Kent (Cooling, for example). Southampton, having been burnt to the ground by the French, underwent extensive reconstruction of its defences, including (early in the fifteenth century) one of the first gun-towers (the God’s House tower).
Amidst all this very expensive work, in 1385, the castle at Bodiam (Sussex) was put up for Sir Edward Dallingridge, set in a lake and pierced with gun loops and now a picture-postcard National Trust attraction. It has been the centre of a battle lasting longer even than the hundred years war. Forty years ago, the late Charles Coulson famously demolished its military pretensions by pointing out its many flaws from a defensive viewpoint. Bodiam became the peaceful retirement home for a military veteran.
Sometimes you only see what you want to see. Actually, Dallingridge wasn’t retired: he was commissioned to review the defences of the coast, for the king, and was actually wounded in a French attack. His gun loops may not have worked very well and his lake could have been drained – but a French raiding party was unlikely to hang around long enough to find out. In the context, the most that can be said is: we don’t know what he intended.
England swiftly lost its leading position in the race to build fortifications adapted for and against artillery as it became significantly more powerful during the course of the next century, a time when the gap between what princes and their subjects could afford expanded greatly. But many nobles did make provision for guns, and kings still put comfort first (Edward III’s work at Windsor). Between the two extremes of fortresses with evident military purpose and castles designed as palatial homes, others tried to provide for both functions, with numerous examples across the continent.
Perhaps that was what the medieval castle had always been?
The buried or below-ground archaeology at castle sites can be exceptionally well preserved because of its burial under masonry. However, it is often overlooked in conservation and management plans in favour of protection and consolidation of standing remains and developments such as reconstruction and rebuilding projects. It provides an important lens through which we can examine important phases and hiatuses in the developmental history of these monuments.
Castle Keverberg (Kessel), the Netherlands, which consisted of an original stone tower built in 1100 and covered by a motte-and-bailey castle;
Several French castles, which are Château de Caen, built in 1060, Château de Gien, which today hosts the National Museum of Hunting with the remains of an early (c. 9th – 11th AD) Carolingian castra below, Château de Loches and Château de Boves;
Two Italian case studies, Castelseprio, a UNESCO World Heritage site, and Montegrotto;
Dunyvaig Castle, Islay, Scotland, formerly the naval fortress of the Lords of the Isles, the chiefs of the Clan MacDonald.
This project developed a framework for geoarchaeological research at European castles to target archaeologists, castle curators and heritage management policy-makers, so that our guidance can influence their future excavation strategies and conservation plans. Geoarchaeology applies environmental science techniques to archaeological research questions. Soil micromorphology is a geoarchaeological technique that enables us to conduct a micro-excavation by analysing a slide, or ‘thin section’, produced from an intact, small block collected from the archaeological stratigraphy, so the inclusions are still in situ. The slide is analysed using a geological polarising microscope. Under the microscope, we record the same soil properties as archaeologists do in the field and additional ones, to understand the processes by which materials were deposited, how they have decayed due to chemical weathering, and how later human and faunal disturbances have affected the stratigraphy.
Soils and sediments are the backbone of the archaeological record. Our data revealed important stories within the soils about the early development of castle sites, the activities that took place inside different areas of the castle and how they may relate to the activities in a castle’s hinterland. We noticed that the preservation of the stratigraphy was exceptional owing to its burial under later masonry structures, masonry collapse and successive occupation layers; a phenomenon which is also observed on urban sites and Near Eastern tell sites.
Our results highlight the great potential and requirement for scientific analysis of these deposits when they are uncovered by excavation and/or building activities. These building activities include the conservation and renovation of the standing architecture and the removal of rubble, which can unseal buried archaeology affecting its preservation. Our analyses have revealed microscopic evidence for in situ animal husbandry and horse stabling, as well as the types of fodder that livestock were fed, crop processing activities, and periods of soil formation where areas of a castle have been abandoned or changed use. For example, at Castillo de Molina de Aragón, Spain, microstratigraphic data show the changing nature of the occupation the citadel, from the Islamic to Christian period which could possibly indicate a change in its role from a clean, well-maintained space to one where livestock roamed. The Islamic plaster floor surface was kept clean and very little domestic refuse accumulated ̶ a soil formed over it, followed by a substantial destruction horizon. In comparison, units of discarded material and trampled floor surfaces characterise the (Re)Conquest phase, c. 1154, and a series of plaster floor surfaces with associated occupation residues containing herbivore dung showing that livestock were present, which probably relate to modifications during the thirteenth and fourteenth centuries.
The number of licences is the most ever given, at one time, to a medieval noble or gentry. You can find them all on the Gatehouse castle gazetteer website[i]. However scrutiny here would indicate that there is little to see now or indeed was in the past. Most of the sites would appear to have been not much more than lightly fortified manor houses. Only at Saffron Walden is there what would be commonly described as a castle. However here and elsewhere there is little evidence that any building work was done by Humphrey.
A possible explanation could be the date. In 1348, the Black Death reached England. It was first recorded at Weymouth in June, reaching London by the autumn and was across all southern England by March 1349. It was only in December 1349 that some form of normality returned.
Like our current pandemic there were drastic consequences with an estimated 40 to 60% of the population dying, the greatest loss being amongst the working classes. There was a curtailment of much activity for instance major campaigns in the 100 Years’ War with France were halted until 1355. Post the pandemic there was a shortage of labour with an increase in wages, meaning building projects would have been more expensive.[ii]
In such a situation did Humphrey cease his building plans? Before jumping to this conclusion we need to probe into the impact on castle construction, the nature of licences to crenellate and the life of Humphrey.
Impact on castle building? The consensus view seems to be, certainly in the long term, this was not great. John Goodall, the eminent castle expert suggests it raised the financial threshold of construction and increased the relative importance of royal works. However it did not “deter the very richest—from embarking on splendid building projects”[iii]
Nature of licences to crenellate? It is not unusual to have licences without ensuing building work. The research of the late Charles Coulson and Phil Davies has highlighted that the true nature of such licences was not to control castle building but for the recipients to obtain the prestige, status and legitimacy of having such documents, whilst also generating revenue to the crown.[iv] Many were made after castle building or were given to buildings with minimal fortifications and many seemed to have led to no construction. The number given to Humphrey whilst high was similar to a few Bishops, for instance the bishop of Salisbury received licences for 10 sites in 1377 and the bishop of Chichester for 12 houses in 1448. Similarly to Humphrey, there was little consequently to see.
Life of Humphrey? Born in 1309 a younger son, inheriting in 1336, he served in the Breton campaigns of the Hundred Years’ War with involvement in the victories of Morlaix (1342) and La Roche-Derrien (1347).[v] However I am unaware of any subsequent campaigning and despite being the Lord High Constable of England he was never a favourite of Edward III. He died in 1361 at Pleshey Castle leaving his nephew as heir.
There is not a simple answer to this plethora of licences and missing castles. It is possible some were to underpin his legitimacy to manors where his inheritance might have been disputed, such as Seend and Upavon. Similarly at Saffron Walden, which had been slighted as a castle during the anarchy. Others might have been to emphasis his premier noble status.
Perhaps what was important pre-pandemic was not so afterwards? The impact on his psychological wellbeing is unknown but might be significant as can occur in our pandemic. In 1350 he commissioned the translation of the romance poem ‘Guillaume de Palerme’. He did not seem to have married or had children.
In my view the answer to this mystery is not simply the pandemic but it might have been a factor. I do think more understanding of his life might be the key.
Steven Spencer and Elena Faraoni of the Hoghton Tower Preservation Trust, look at the results of their work, funded by the Castle Studies Trust in 2019, in trying to find out more about Hoghton Tower in Lancashire.
Hoghton Tower sits 650 ft above sea-level in the heart of the Lancashire countryside. The stories of its visitors and family members are documented and shared whether it be in books, portraits, family albums or documents in the Lancashire archives. But there is one story which has always intrigued us and that is: what was the first tower of Hoghton Tower and where was it? It is clear when looking at the building today that this, like many other historic houses, is a ‘patchwork’ of different projects by different generations interlaced and blended…but where did Hoghton Tower start? Where was the original tower?
There are some clues: the ageing of the stone, the position of the well house, family stories passed down the generations, the shape of the windows and a mysterious mound of stones on the north side of the buildings. One of these stones has an intriguing mason’s mark… Spurred on by the interest of a group of our amazing volunteers who had just finished some research into historic graffiti and masons’ marks it was time to do some investigation under the guidance of Dr Mike Nevell and his team at Salford University. We designed a research project based on archaeological digs, building recording, geophysics and archives research based on the key exam question “where was the great keep of the Hoghton Tower hill?”
Thanks to the grant from the Castle Studies Trust, work quickly got underway. Through a series of Salford-led workshops, the team surveyed, recorded and reviewed old photographs and pictures.
Then there was the wonderful five-day archaeological dig.
As they passed through the perimeter fencing on to the dig site, the usually mild-mannered volunteers underwent personality transformations as pairs of friends and even married couples were ‘pitted’ against one another. Was this the site of a 14th century Pele Tower, a 1643 victim of the First Civil War, who would make the crucial find?
Under the patient guidance and control of the Salford team, the test pits were marked out and the excavations began, to many this was the chance of a lifetime and was eagerly embraced. Each find was announced with enthusiastic shouting from the discoverer and muted derision from those yet to make a meaningful contribution.
As the week progressed, 14th to 19th century finds were unearthed, thankfully shared out between the eight test pits. Clay pipe bowls (1640 to 1680), a musket ball, heat affected glass, sherds of medieval pottery and fragments of medieval roof tiles. Below a stone rubble layer, evidence of a stone-built structure was revealed in the form of large dressed stone blocks, together with walls and a stone flagged floor.
Spurred on by the whole experience, and encouraged by the de Hoghton family, the volunteers have produced and presented an ‘Outdoor History’ tour which aims to share the latest thoughts and discoveries.
Was this the site of the Hoghton Tower? Did we find anything categorical? Well yes and no. The archaeology revealed previously unrecorded stone structures. These together with the artefactual evidence were able to confirm that this part of the hilltop was occupied during the late medieval/early post-medieval periods. The geophysics also gave us other areas that warrant more digging and researching. So, some confirmation but also a lot more to understand and discover on this windswept hill!
Hello! A personal introduction before we get down to the geophysics. I’m Kayt Armstrong, and I am an advisor to the Castle Studies Trust as a specialist in the use of geophysics in archaeology. I am also a member of the board of the International Society for Archaeological Prospection, and I represent the UK on a European research network about soils and geophysics in archaeology. I obtained my PhD in Archaeological Geophysics from Bournemouth University in 2010. I have worked in the UK and Europe (Greece and Italy) since that time, conducting archaeological geophysics in a variety of research and developer-led contexts. I help the CST evaluate funding applications that have geophysical elements, and also comment on the reports from any resulting work.
If you were a Time Team enthusiast, you probably already know the answer to this one!
Geophysics is the study of the physical properties of the earth (or other planets – you can do astrogeophysics!). It is an extensive term that encompasses whole planets, right down to understanding the microstructures of stone. Archaeological geophysics falls into ‘near-surface geophysics’, which studies the first 30m or so of the ground. In fact, commonly, archaeological geophysics is only really concerned with the top 2m or so; material in the topsoil, rather than the bedrock.
Geophysicists use a variety of methods and instruments to get information about the physical properties of the ground, such as its ability to conduct electricity, or its magnetic properties. Small variations in those properties can then be mapped. Buried archaeological material causes variations in the properties in predictable ways. This means we can map buried archaeology using these methods, without having to dig everything up.
When it comes to Castles, there are three main geophysical methods: earth resistance (‘resistivity’), magnetometry, and ground-penetrating radar (GPR). All three techniques look at slightly different aspects of the sub-surface, and all three have benefits and weaknesses. It is really best to combine methods to get as complete a picture as possible, as they will all tell you slightly different things.
Magnetometry is probably the most commonly used technique in archaeology. It uses sensors to look at small variations in the strength of the earth’s magnetic field, to look for changes caused by buried material. The soil on sites where humans live becomes more magnetic over time, due to things like fires for cooking and warmth and the fermentation of waste material. This material becomes the fills of cut features like pits and ditches. These end up more magnetic than the soil they are cut into.
Structures used for processes involving heating, such as kilns, furnaces and ovens, become even more strongly magnetised and have a very characteristic appearance in the data. Similarly, fired ceramic building materials like brick or tile have a distinctive signal, as do igneous or metamorphic rocks (those modified by heating during their formation).
Magnetometry is very fast, covering upwards of 10ha a day if using the latest equipment. It is also relatively easy for community groups to employ. However, the pace will be somewhat slower using hand-carried single sensors. The plus-sides are the speed of survey and the wide variety of archaeological features that can be detected and mapped. The downsides are that this method is strongly disrupted by ferrous material in the survey environment, and has problems on igneous and metamorphic geologies as happened with the survey of Tibbers in 2014. It is also not very useful for mapping stone remains that are not strongly magnetic (such as some sandstones and most limestones). Modern infrastructure within or adjacent to the survey area has a far greater impact on the results than any buried archaeology (as happened in the Wressle survey of 2019), masking it from detection. It is practically not possible to use this method in urban areas. This method cannot detect smaller structures if they are buried more than about 2m below the ground surface. Features in the first 2m can usually be detected but the size of the anomalies that can be distinguished depends on the resolution of the readings taken. However, this method doesn’t let you understand the depths of the anomalies, and so isn’t as helpful on multi-period sites.
Earth resistance examines how easy it is to pass an electrical current through the ground. The resistivity of the subsurface varies in relation to several properties. Still, the most substantial effect is caused by variations in moisture content. The fills of cut features like pits and ditches (as witnessed in the 2018 survey at Laughton which showed a possible ditch, confirmed in the 2019 excavation and of Tibbers which lead to the discovery of a new inner bailey) tend to have a more open texture than natural soil. They usually also contain more organic matter. This means they are generally wetter than the ground they are dug into. Conversely, buried structures like walls and floors, are usually much drier than the material surrounding them, because they can’t absorb as much water.
This technique can be applied in two ways. You can collect a grid of readings over a flat area to examine the first 2m or so, producing a plan view. You can also collect long lines of readings with increasingly wide measurement points. This is called ‘Electrical Resistance Tomography’ or ERT, and produces vertical pseudo-sections through the ground, and can reach greater depths, typically in archaeology 8-10m.
The plan-view method typically involves 2 probes on a mobile frame, and two remote probes connected by a cable. 2 of the probes inject a current, and two measure the resistance to it. It is especially useful for mapping buried stone structures. It is therefore handy on ‘Castle’ sites where multiple building phases can be expected. It is relatively slow, however, and relies on being able to insert probes into the ground to get the readings. This is fine on a lawn or field, and it can work on paths and gravel, but the results get very noisy, and it isn’t possible over flagstones or tarmac or concrete. You also need to be able to manoeuvre the cables and place the remote probes at an appropriate distance. This method also doesn’t let you understand the relative depths of various anomalies.
ERT is less commonly used in archaeology, but it has some specific applications in the study of large defended sites. Because it can resolve structures at a greater depth than the plan-mode, it can be used to examine the construction of large structures. This includes moats, earthen banks and buried fortification walls, and other such features. If multiple adjacent profiles are collected, the data can be combined into a 3D model of the subsurface, which can help resolve questions about the construction sequence of a site.
Twin-probe (plan-view) resistivity survey is relatively straightforward to carry out. It doesn’t require as much skill on behalf of the instrument operator as magnetometry does. It is however, slow and laborious. The equipment is relatively cheap, and data processing and visualisation are relatively simple. This method is rarely used in the commercial sector these days but is an ideal research tool. Community groups have produced excellent research using this technique. The ERT method requires specialised equipment and a trained collector. The background knowledge needed to correctly process and interpret the data is also high.
Ground Penetrating Radar
GPR only made the odd appearance on Time Team, but in the last decade or so advances in computing (mostly increasing miniaturisation of components, and improvements in battery life) have led to a new generation of GPR kit that is more flexible and affordable.
GPR works a lot like sonar or the sort of radar employed by aircraft. A transmitting antenna sends out radio waves focused into the ground. These propagate downwards and are reflected by abrupt changes in the material of the subsurface. For example, when the waves leave a stone ceiling and move into the vault, some of the waves will be reflected back up. Some will continue on, to encounter the floor of the vault, and anything below it. The reflected waves are collected by a receiving antenna (usually in the same ‘box’ as the transmitter, a fixed distance apart). The strength of the returned waves, along with the time (in nanoseconds!) it takes for them to return is logged and plotted. This is a single trace.
The antenna is dragged along a line, and a series of traces are collected at a small interval (usually every 5cm or 2cm), which are combined together to make a profile. This is effectively a vertical slice through the ground. These are a bit difficult to read because the radio waves emit in a curved shape, so they actually travel in front of and behind the antenna, not just directly under it. This creates distinctive hyperbolas in the data. The depth of signal penetration and the size of the objects you can detect varies with antenna frequency. Depending on the frequency of the antenna, you can look very shallowly and resolve things that are a centimetre (or less) across. Very high-frequency antennas are used to assess the structure of concrete in civil engineering or to image different layers in mosaics and floor coverings. Lower frequency antennas cannot resolve smaller anomalies but can penetrate 10m+ to resolve much larger objects, such as former river beds, large walls or banks and ditches.
Groups of profiles collected in parallel lines can be combined together to make a 3D block of data. This can be processed in a way that allows different horizontal depth slices to be examined (as done at Fotheringhays; see time slice). A new generation of GPR system uses lots of antennas in an array to collect very high- resolution datasets (8cm in all directions), or arrays of different frequencies to quickly collect data with good resolution at multiple depths.
GPR requires a skilled operator to plan the work, collect the data and the process and analyse the results, but it is arguably the best technique for investigating Castle sites. This is because it tends to be good at detecting the sorts of things we would expect to be looking for, for example, voids, buried walls, culverts and surfaces. It can also be deployed inside standing buildings, to look underneath floors or behind walls. It can be used over tarmac and concrete (providing the concrete is not re-inforced!) and does well on most geologies, except for certain kinds of clays, and saline environments like estuaries.
The other advantage of GPR is that the data is relatively fast to collect, compared to earth resistance, and a broader range of features can be detected with it. It is also an inherently 3D method and allows complicated below-ground sequences to be visualised and interpreted. I have seen examples of staircases being visible in the data from 3D GPR, for instance. This technique has made the headlines recently, with the publication of a study of an entire Roman city, Falerii Novi, just north of Rome, by colleagues of mine from Ghent University and Cambridge University.
Geophysics and the Castle Studies Trust
Geophysical approaches form an increasing component of research proposals put to the trust, which is excellent to see! Geophysics can help to answer both broad and specific questions about castle-sites, without the potentially destructive process of excavation. Geophysics also has applications for the conservation of sites and planning for their future management. For example, in mapping the integrity of standing walls using GPR, or understanding the soils and material within earthworks to protect them from erosion in extreme weather events. They can help site managers decide whether an intervention is necessary, and can inform the design of any needed work. Geophysics can also play an essential role in the continuing life of these sites as homes or places of historical interest by mapping areas where conservation or building work is planned to ensure nothing is damaged by the work.