below Recent archaeological investigations at Ankerwycke, near Wraysbury in Berkshire, have shed vivid light on a ruinous structure that once formed part of a medieval nunnery.

Excavating Ankerwycke: From priory to pleasure ground

For the last two years, archaeologists have been exploring the remains of a medieval nunnery that once occupied the bank of the Thames opposite to where Magna Carta was signed. Carly Hilts met James Brown on site to learn more.


On 10 June 1215, King John met some of his barons on the Thameside water meadow at Runnymede. Despite the illustrious company and the colourful display that this gathering must have represented, tensions were high. England was teetering on the brink of civil war, as the barons had risen up against John’s absolutist rule and high taxes. Over the next few days, negotiations mediated by the Archbishop of Canterbury crafted their list of demands into a peace agreement to which John finally put his seal on 15 June. Although the barons had primarily sought to protect their own property and privileges, the ‘Great Charter’, or Magna Carta, was revolutionary, formally limiting the power of the Crown and stipulating that the king and his government were not above the law. (See CA 304 for a more detailed exploration of the document’s significance, and research that marked its 800th anniversary in 2015.)

below Recent archaeological investigations at Ankerwycke, near Wraysbury in Berkshire, have shed vivid light on a ruinous structure that once formed part of a medieval nunnery.
Recent archaeological investigations at Ankerwycke, near Wraysbury in Berkshire, have shed vivid light on a ruinous structure that once formed part of a medieval nunnery.

While these historic events unfolded amid emblems of military might and royal regalia, a rather humbler group of witnesses may have been watching from the other side of the river. The nuns of St Mary’s Priory – a small Benedictine community at Ankerwycke, near Wraysbury in Berkshire – had occupied the land directly opposite Runnymede since the 1160s. The spectacle must have seemed worlds away from their quiet lives of contemplation, and they may have taken a particular interest in the proceedings as one of the barons (Richard de Montfichet) was their founder’s grandson.

This scenario, however, remains only plausible. Historical references to the nunnery are fleeting, limited to a legal agreement from the reign of Henry III, granting the nuns licence to turn out their pigs in Windsor Forest, a priory seal from 1199, and rather more colourful footnotes in accounts of visits from the presiding bishop of the time. In 1197, for example, we hear (in Curia Regis rolls: records of the royal court) of a nun who ran away from St Mary’s, claiming that she had been forced to join the priory in order to cheat her out of a rightful inheritance. After the Pope became involved, she was ordered to return and ultimately excommunicated. Meanwhile, in 1441, an account of a visitation by Alnwick, Bishop of Lincoln, reports that the nuns were complaining about the abbess blocking up their dormitory windows (their leader in turn claimed that this was because they kept talking to men on the riverside). Such records also preserve further complaints about buildings being in a poor state of repair and the abbess wasting the priory’s goods while being very austere in her treatment of the nuns; and when Bishop Atwater, again from Lincoln, visited in 1519, he learned that another nun, one Alice Hubbart, had run away, this time to get married.

Contemporary references to St Mary’s Priory are relatively limited, but one depiction of the nunnery’s church survives on this 12th-century seal. Surviving historical documents provide further glimpses of the buildings  that once made up the religious complex, but their layout and relationships were poorly understood. Image: National Archives

Such scandalous stories read like a soap opera; what we have rather less of is any account of the nunnery’s day-to-day operations, or any description of how its buildings related to each other or their layout. All we can be reasonably confident about is that the community appears to have remained fairly small and poor, and that, after the Dissolution of the Monasteries, the site was drawn firmly into the secular world, becoming the home of various wealthy members of the laity who were favoured by the Crown. By the 1550s, the land at Ankerwycke had been acquired by Sir Thomas Smith, who promptly converted some of the priory buildings into a smart winged residence and demolished most of the site, retaining only a few of the nun’s barns.

This house met its end, too, in the early 19th century when its then-owner, John Blagrove, abandoned the small, dark, and flood-prone site for a brighter, drier, and more comfortable Georgian mansion that stood a short distance to the north until the 1990s. Its Tudor predecessor was swept away, leaving a single L-shaped fragment of upstanding masonry to adorn Blagrove’s estate as a romantic ruin. The rest of the priory grounds became a 19th-century pleasure ground, but today all trace of this once-bustling landscape has vanished, and the green tranquillity of modern Ankerwycke gives a sense of seclusion (apart from the regular overhead passage of planes from Heathrow) that belies the crowds that must have once thronged this portion of the riverside.

Interpretation of recent geophysical surveys at Ankerwycke  were greatly aided by aerial photographs – such as this image from 1953, which shows preparations ahead of the unveiling of the Runnymede Air Forces Memorial on the opposite bank – which document some  of the (now-vanished) structures that stood  on the site in recent decades. Other anomalies were found to represent medieval and Tudor features, however. Image: Historic England

The site has been in the care of the National Trust since the 1990s, and over the last two years archaeologists have been working to learn more about Ankerwycke’s past, and to illuminate the lives of the nuns beyond the scurrilous references created by male clerics. These investigations have been carried out by the National Trust, Surrey County Archaeological Unit, and an army of volunteers as part of the wider Runnymede Explored Project (a five-year initiative, supported by the National Lottery Heritage Fund, which is focused on improving public understanding of, and access to, the historic sites on both sides of the river). This summer, I visited the latest excavations with National Trust archaeologist James Brown to learn more.

Analysis of Ankerwycke’s upstanding remains revealed that they represent the corner of two external walls that once belonged to a two-storey building. What was the purpose of this structure (shown being worked on by Cliveden Conservation)?

Cloistral clues

After a stuttering start at the outset of the COVID-19 pandemic, NHLF funding during 2020/2021 allowed the National Trust (with the help of Berkshire Archaeological Society) to carry out much more extensive geophysical surveys than Ankerwycke had previously seen, revealing that the land between the L-shaped ruin and the river was busy with features invisible to the naked eye. Some of the features were easy to identify and cross-reference with known activity on the site, among them, boat- and picnic houses besides the Thames which had been enjoyed by patrons of the pleasure ground, as well as a filled-in swimming pool and its boiler room from the 1940s. Many others, however (described by James as a ‘hotchpotch of straight lines and right angles’) were suspected to be much earlier in date – leading to long discussions about what might represent Tudor remains and what might be surviving traces of the medieval nunnery.

While addressing these anomalies and sharing the story of the site with visitors, a key question for the 2022 season was to establish the probable purpose of the building that the L-shaped remains belonged to, and whether they were an original structure or a fabricated folly created from demolished medieval materials during 19th-century landscaping. Careful examination of their fabric suggests that they represent the chalk core of a corner formed by two external walls (as evidenced by the surviving stub of a buttress protruding from one of them), while the presence of a small ‘lip’ on their outer surface and putlogs hint that the structure once had a second storey. Analysis of mortar samples supported suggestions that the ruin had formed part of the site’s early history – but what was this once-imposing structure for?

Given its size, initial interpretations suggested that it might be the refectory, where the nuns ate their daily meals, or perhaps the priory church. The former might be a more likely candidate for conversion into a Tudor house, but in order to help narrow options down the team set out to locate the remains of the cloister. In a male monastic community, this would typically lie to the south of the church – but, James noted, when researching Ankerwycke and comparable sites the team found that the relatively smaller number of nunneries that have been excavated, or which have survived unaltered to the present day, meant that a ‘typical’ design for a female community was harder to pin down. Persuasive arguments for the cloister lying to the north or to the south of the ruin were put forward and, in 2022, a search began. As this work started, it was not known how thorough Tudor demolition of the medieval remains had been, and the diggers were initially discouraged when their northern trench came down on quantities of orange river gravel. Beneath this, however, they found the remains of chalk structures; rather than clearing the earlier foundations, it appeared that the Tudor builders had levelled the site by burying them beneath a thick layer of gravel dragged from the Thames, providing some flood protection for the site and, crucially for the site’s more modern visitors, preserving invaluable clues underneath.

Above and below: Drawing on historical research and findings from the recent excavations, Phil Kenning’s reconstructions show Ankerwycke’s medieval priory (focused on the cloister, with church and refectory in either side) and the Tudor residence with its formal gardens that replaced the religious community. In both images, the L-shaped ruin belonged to the building at the centre with the triangular buttress. 

The foundations that emerged did indeed prove to be part of the cloister, namely the north-east corner of a covered walkway that would have surrounded an open courtyard known as the cloister garth. Such descriptions might evoke images of a lofty passageway with high stone arches, as is known from other monastic sites, but in keeping with a small and impoverished community, the Ankerwycke walkway was a rather less elaborate affair, comprising a low chalk wall that may have been topped with a timber lean-to superstructure and possibly a tiled roof. Stacks of more tiles, mortared together, had been used to line the inner face of the walkway’s walls, and it is possible that this space (or another priory building) had been adorned with a decorative tiled floor, as two such fragments have been found on the site to-date, albeit neither in situ. While their imagery is too incomplete to interpret, elements of the tiles’ design hint at an artistic connection with Chertsey Abbey, which once stood about five miles to the south- east and also made extensive use of chalk in its buildings.

In the corner of the trench, running parallel to and just to the north of the walkway, were the lower courses of another, much more substantial wall. This was about twice as thick as that of the cloister and, given its size and location, has been interpreted as possibly representing part of the priory church. The L-shaped ruin, which lies to the south of the cloister remains, is therefore thought to reflect a portion of the nuns’ refectory. Together, these three structures would have formed the heart of the religious complex, surrounded by a working landscape dedicated to sustaining and supporting the community’s self-sufficient and introspective way of life.

Tudor transformation

During the Tudor period, this landscape saw a marked change of emphasis, becoming more self-consciously outward-looking and concerned with display. The nearby waters of the Thames were no longer a boundary from the secular world and a convenient source of food; they now served as a highway to the fashionable delights of the royal court at Windsor, while Smith’s new house overlooking the river was a highly visible celebration of his family’s status.

RIGHT One of the key discoveries from this year’s excavations was a stone threshold and accompanying stone jamb, which allowed the team to establish the width of the original medieval structure now surviving only as the L-shaped ruin.
One of the key discoveries from this year’s excavations was a stone threshold and accompanying stone jamb, which allowed the team to establish the width of the original medieval structure now surviving only as the L-shaped ruin.

Part of this change saw productive areas transformed into elegant formal gardens, which were also explored during last year’s investigations. A second trench was opened south of the ruins on a large square platform that could have held a cloister, but geophysical survey had revealed an enigmatic cross shape, as had parchmarks in particularly dry weather. These markings proved to be the remains of gravel paths that once divided the gardens into quarters, and the same trench uncovered a brick retaining wall that once bordered this space. There were quantities of chalk rubble, too – material from demolished medieval structures – which, together with the river gravel, had been used to raise the ground level for the garden. While the excavations did reach underlying medieval layers on this part of the site, they simply represented the natural ground surface of the time; no sign of medieval structures or other features were found there, although pieces of boar tusk and medieval pottery were recovered.

LEFT Part of the north-east corner of the cloister. On the right side of the trench is the potential church wall that runs east west with the east end aligning with the Ankerwycke Yew.
Part of the north-east corner of the cloister. On the right side of the trench is the potential church wall that runs east west with the east end aligning with the Ankerwycke Yew.

As for this year’s work, the project team have been exploring the L-shaped ruin in more detail. While only a corner of the structure survives, it offers vivid insights into the many alterations that the building saw throughout its life. Tacked on to the edge of a medieval chalk wall, James showed me a Tudor brick pillar, while a post-Tudor fireplace had been inserted into its internal face. There was also a medieval threshold stone, preserved in situ beneath the Tudor landscaping – a fortunate survival, as it allows the team to define the width of the original medieval structure and how it may have been linked to the cloister. More surprising was the discovery of a series of Tudor steps leading down at least a metre (the bottom of the flight has not been reached) into a presumed cellar or vault that, given the watery nature of the site, had not been anticipated. They were constructed from brick, tile, and mortar, and the front of each tread appears to have been faced with wood, as evidenced by surviving traces of this material and small cuts in the adjacent masonry.

In addition to the archaeologists investigating the remains, the L-shaped ruin has been the focus of ongoing work by Cliveden Conservation (also funded by the NLHF), whose efforts are intended to consolidate the weather-eroded chalk and slow any further decline. As well as repointing crumbling or lost mortar, and soft-capping the tops of walls, the team of specialists have been contending with the effects of well-intentioned but ultimately harmful historical hard interventions. In the 20th century, James said, repairs to the ruins had essentially involved ‘slapping concrete on, and sticking chalk to the outside’. Today, this additional material is weighing heavily on the fragile remains and, while its removal means that, in some places, the ruins have now reduced in height, they are now more authentic, and more stable. The conservation of these remains was carefully considered, but as they represent the last remaining visual cue for such a fascinating location with so many stories to share, James noted, it was clear that the priority needed to be prolonging its life and using it as a stepping stone to help illuminate the wider site for visitors.

As well as archaeological research, the present project has seen the Ankerwycke ruins being preserved by Cliveden Conservation. Here we see hot-mixed lime mortar being used to consolidate the medieval chalk.
Insights into the many alterations that the building had seen over its lifetime. To the right, we can see a Tudor brick pillar added to the end of a medieval wall, and, in front of this, a flight of steps that also date to the Tudor period. On the opposite side of the wall was a post-Tudor fireplace.

Tangible traces

Away from the chalk ruin, the excavation team wanted to investigate how the frequently flooded landscape had been managed over the centuries. To that end, this year they have opened a trench just outside the Tudor retaining wall, revealing an underlying ground surface striped with distinct bands of clay, silt, and gravel, as well as quantities of dumped material. While the contents of this trench are perhaps not as visually arresting as the priory remains, James said, they paint a particularly vivid picture of how the site has been used over time. One of the stripes has been interpreted as a possible robber trench for a medieval wall – only a narrow one, but if it had demarcated the priory precinct, it only needed to provide a symbolic boundary rather than a major defensive feature – and, outside this line, the team found significant quantities of medieval refuse. Tellingly, the equivalent Tudor material appeared to have been dumped elsewhere, suggesting that once this part of the site had become a garden intended to be seen and admired from the river, rather than representing the boundary of an inward-looking religious cloistered community, rubbish was unsurprisingly being discarded somewhere else.

Among the discarded medieval material, one tiny find offered a clear link to the site’s religious past. This was a coin, a silver halfpenny with a ‘long cross’ design that may have arrived at Ankerwycke only a generation or two after Magna Carta was signed on the opposite riverbank, as it dates from the second half of the reign of John’s successor, Henry III (specifically, to AD 1250-1272). It had been carefully folded in half which, in the medieval period, was a devotional gesture: a poignant, tactile echo of religious activity when the nunnery was still occupied.

 This silver halfpenny of Henry III had been folded in half as a devotional gesture.

The redeposited layers from which the coin came also yielded a diverse range of finds that spanned much of the site’s life: medieval green-glazed pottery and glossy black Cistercian ware from the Tudor period; a spoon; fragments of glass vessels; musket balls; and pieces of clay tobacco pipes that may have been enjoyed by the 19th-century pleasure ground’s patrons. Among this mass of material, though, there was a possible link to the nuns themselves: a little pin that would have been used to secure clothing or perhaps a veil. At the time of my visit, only one had been discovered during this year’s excavations, but it joined a large number recovered from the cloister remains in 2022: fitting finds for a project that is working to piece together the experiences of a community that has otherwise only been described by disapproving outsiders. Even Ankerwycke’s name, which evokes medieval religious recluses known as anchorites (or, for women, anchoresses), speaks to a long association with Christian activity beside the river, perhaps even pre-dating the establishment of the priory. The recent archaeological investigations and close work with illustrator Phil Kenning have resulted in two artistic reconstructions of medieval and Tudor Ankerwycke, helping to bring the site back to life for visitors through new interpretation.

Project volunteers excavate an area on the boundary of the priory grounds, overseen by site-dog Toby.

Source: James Brown is a National Trust Archaeologist for the London & South East Region.

Further information:
• To read more about the Runnymede Explored Project, visit visit/surrey/runnymede-and-ankerwycke/runnymede-explored-project.
• If you go to and search for ‘Ankerwycke’, you can also explore interactive 3D models of the L-shaped ruin and the trench opened beside it this year; the cloister remains excavated in 2022; and last year’s Trench 2, which investigated the Tudor garden. These form part of ‘Surrey Landscapes’, a collection of 3D models by National Trust Archaeology.
• Excavation reports can be accessed online via https://heritagerecords.nationaltrust.; search for MNA147259 to read more about the Ankerwycke investigations.

Photos: National Trust, unless otherwise stated