In 1414, Henry V began an ambitious project to rebuild Shene Palace (Richmond Palace, see CA 193) as his Lancastrian dynastic seat, and to establish three great religious houses on the banks of the River Thames within sight of the royal residence. One was Shene Charterhouse, a Carthusian priory founded in September 1414, while Syon Abbey, a Bridgettine house, was founded in February 1415 in Twickenham, on the riverbank opposite the palace. But the site of the abbey was cramped and damp, so in 1431 the Bridgettines moved to Isleworth, in what is now Syon Park. It is the remains of the re-established abbey that we will explore here. Henry also began construction of a French Celestine monastery, but the outbreak of war with France put an end to this initiative.
When Henry died in 1422, Shene Charterhouse may have been substantially finished, but he did not live to see the relocated Syon Abbey, as work did not begin at Isleworth until 1426. It was left to his son, Henry VI, and other benefactors to see its completion. Syon’s church was finally consecrated in October 1488, by which time all the essential elements of the abbey were in place.

A Swedish model for Syon
What is a Bridgettine house? The Bridgettine Order was founded by Birgitta (Bridget) Birgersdotter (1304-1373), a Swedish noblewoman who was canonised in 1391. Birgitta embraced the religious life after her husband’s death, establishing an abbey at Vadstena, Sweden, whose community followed the Augustinian Rule, albeit modified by the ‘Rule of the Saviour’ revealed to her by Christ in a vision. St Bridget’s Rule influenced the size and layout of daughter-houses like Syon Abbey, for it specified that each Bridgettine monastery should comprise 60 sisters and 25 brothers, and that the abbess should rule both communities in worldly matters, while the confessor general provided spiritual guidance.
The Rule also stipulated that the sisters should have their own strictly enclosed convent and cloister on the north side of the church, while the brothers would occupy buildings on the south side. Segregation was to be maintained in the church too, with a raised choir in the eastern part of the building for the sisters, while the brothers’ choir would be at ground level at the west end, behind the high altar. Syon’s community was eager to copy the mother-house’s design, sending two brothers to Vadstena in 1427 to measure the grounds and enquire about the size of the enclosed areas needed for the sisters and brothers. They even sought papal permission, during construction of their church, to place the high altar near the west end, as at Vadstena.
A landscape shaped by kings
The Bridgettine and Carthusian houses represented a late isolated flowering of medieval monasticism, and together with the royal palace they provided an impressive backdrop for many important historical events in late medieval and Tudor England. This landscape also gained two modest late additions: the Hospital of the Virgin Mary and the Nine Orders of Holy Angels, founded in 1449 on land between Syon Abbey and the River Brent, and a house of Franciscan Observant friars, established by Henry VII next to Richmond Palace in c.1501.
Syon’s community was admired for its piety and strict religious observance. Many of its sisters came from the families of landed gentry and London’s governing elite, and its brothers included scholars from Cambridge and Oxford renowned for their erudition. There was also a substantial lay population, including elite residents like Margaret Holland, Duchess of Clarence. Even after relocating, the nunnery was just 1.5 miles from Shene Palace by boat, and this proximity greatly boosted its reputation and influence, with the abbey enjoying the patronage of kings and others of high rank. It was also an important pilgrimage destination, conveniently located just ten miles from the capital, between the major routes of the River Thames and the old Roman road from London to the west (now the A315; see CA 260 for more on Roman roadside remains at Syon Park). Pilgrims flocked to receive indulgences and listen to sermons on the site. By the time of its suppression, Syon was the wealthiest nunnery in England and the tenth richest religious house.

This success was not to last, however. Syon Abbey was closed in 1539 amid the Dissolution of the Monasteries, and most of its buildings were demolished by the Duke of Somerset in the late 1540s to make way for his new residence (Syon House). Shene Charterhouse suffered a similar fate, although a few of its buildings survived until the mid-17th century. In the final years of Mary I’s reign, both houses were briefly restored, and even 40 years after their final closure Shakespeare immortalised them as ‘two chantries where the sad and solemn priests still sing…’ (Henry V IV.i). The abbey’s appearance, however, faded from memory.

Time Team investigates
In the late 1990s, almost nothing was known about the physical nature of Syon Abbey, for there were no known contemporary plans, pictures, or descriptions of the religious house, and visible remains were scant. Even the location of the large abbey church was long forgotten. Since then, however, details of the abbey’s layout have begun to come to light once more.
The first major advance was made by Time Team, who were guided by a geophysical survey image of archaeological remains beneath the lawns next to Syon House (CA 192). This showed in ghostly outline the parterres and avenues of 17th- and 18th-century formal gardens, but also features probably representing abbey buildings. Two long parallel lines to the east of Syon House caught the eye of the guest expert, architectural historian Dr Jonathan Foyle, who suggested that they might reflect the north and south walls of a very large church – the widest of medieval date ‘ever recorded in England’. This was confirmed by the first trench; others revealed massively buttressed corners at the east end of the building. Finding the church was a significant development, for this was the heart of the abbey and its position indicated where the quarters of the sisters and brothers should lie.

The arrangement of piers inside the church was puzzling, however. Geophysical survey had recorded four roughly circular features apparently marking the position of piers in two arcades, which would have divided the church into three aisles. But further east, in the first trench, only one central pier base was found, suggesting that the eastern part of the church only had two aisles. Jonathan offered possible explanations for the anomalous pier, hitting the mark with his suggestion that it may have supported a raised choir.
There was great excitement when it was noticed that the north wall of the abbey church lined up with a section of early stone masonry incorporated in the base of the northern wall of the central courtyard of Syon House. This was taken as evidence that the church was at least 200ft long, and that it may even have been a massive ten-bay building extending almost up to where the west front of Syon House now stands, making it about 370ft long.

To the south of the church, part of a cloistered building was uncovered, with two graves containing female skeletons. These were interpreted as nuns, which led to the assumption that the sisters at Syon lived on the south side of the church rather than the north. A nearby ‘brick tunnel-vault’ with four square openings in its roof was identified as the site of the sisters’ latrines over ‘the great drain running down to the river’. However, Time Team’s three-day format meant that the team of just over a dozen hard-pressed diggers (including me) missed important clues, especially in the partially excavated first trench, where we now know arcade pier bases and brick-lined graves lay hidden. But another chapter of discovery was about to open.
Reconstructing the abbey church
From 2004 to 2011, training and research excavations were undertaken every summer by Birkbeck, University of London, assisted by Museum of London Archaeology and generously supported by His Grace the Duke of Northumberland. These more leisurely and extensive excavations revealed much more of the abbey, and changed our thinking about its layout.
The abbey church was one of the main targets. Built between 1426 and 1488, it would have had much in common architecturally with the chapels at Eton College (1441-1475) and King’s College, Cambridge (1446-1515), also built by Henry VI. It would have been built largely of stone, including fine limestone from Caen in Normandy and Huddleston in Yorkshire, with typically English features in Perpendicular style, although some architectural stone recovered from the site also reflects Continental influences. Its layout, however, was radically different from other English churches. Excavation showed that the eastern half was remarkably similar in plan to the mother-church at Vadstena. From this we conjectured that the unexcavated parts of the building would also closely follow the Swedish design, concluding with some confidence that the main part of Syon’s church had five bays and would have been about 190ft long and 118ft wide. The brothers’ choir at the west end of the church would have been nearly 40ft long, bringing the total length of Syon’s church to c.230ft.

It is now clear that the church was divided into three aisles by two arcades carried on piers. Additional piers in the eastern half of the building supported the sisters’ raised choir, which was rather like a mezzanine floor overlooking much of the church, including the high altar to the west. The choir probably extended to the east end of the church, where a bridging structure supported a raised altar, which documentary evidence suggests extended over a chapel at ground level. The western part of the church was not excavated, but if it also followed the Vadstena plan there would have been 12 small altars on a broad flight of steps leading up from the nave to the high altar, with the brothers’ choir beyond.
Inside the church, passages ran along the north and south walls. These were screened from the rest of the church by shoulder-high iron grilles. Each contained 15 pairs of brick-lined graves for the Bridgettine community: northern ones for the sisters, southern ones for the brothers. Each burial place was numbered, and the Syon Martiloge, an invaluable contemporary source, lists those buried there by name. From this it was possible to identify the fragmentary skeletons of sisters Joanna Spycer and Joanna Rush, and brothers Robert Brerton, William Bond, Anthony Spenser, Oliver Parsons, and William Barnard. None had coffins, and it seems likely that all had been buried in chests of ‘wide lattice work’ as specified in the Syon Additions to the Rule. Most graves had been almost completely removed by later garden landscaping – on one occasion workmen collected ‘seven barrels of human bones’ – but three other graves were found in the church: two near the northern arcade, and one brick-lined grave in the putative chapel at the east end, all containing fragmentary skeletons and traces of coffins.
Sisters and brothers
Two cloistered buildings (B3 and B4) to the north of the church formed part of the sisters’ enclosed convent. There was no evidence to indicate their specific use, but similarly located buildings of known function at Vadstena suggest that the ground floor of the east range may have housed the sisters’ infirmary and associated stores, while the north range contained the chapter house, an entrance hall, an auditorium, and a workroom on the ground floor, with a dormitory above. It is likely that there would have been another cloistered range on the west side of the garth, which may have housed the sisters’ kitchen and refectory, and a substantial stone and brick drain beneath the sisters’ cloister garth and east range must have eventually discharged into the river.


A walled area with a well on the east side of B3 was possibly the convent garden mentioned in accounts of 1501-1502; its location next to the putative infirmary would have been convenient for the cultivation of medicinal plants, which would have been described in a herbal compiled by the abbey librarian Thomas Betson before his death in 1517. Documentary and archaeological evidence suggests that the convent, like most of the abbey, would have been made chiefly of brick, although stone was used in foundations, and probably for dressing doorways and windows.
The remains of three buildings to the south of the church probably represented the brothers’ living quarters. They included two cloistered ranges on the east and south sides of a garth, mirroring the layout of the convent, but they were smaller than the sisters’ buildings, reflecting the relatively small size of the male community. One room in the south range possibly served as a refectory, for there may have been an external stair leading to a pulpit in the south-east corner of the room, and a drain in the adjacent cloister walk could have served a lavabo. Twenty-one graves were found in the cloister walks and garth, of which 17 were excavated (including the two recorded by Time Team). They contained the skeletons of 16 adults (five men and 11 women) and a child of at least eight or nine years, all in wooden coffins. Perhaps they were laity connected to the abbey as servants, residents, or benefactors, or through familial relationships with community.
The third building was a brick cesspit (B7) on the southern edge of the abbey complex, on which a latrine block would have been founded. It was fed by four square vertical chutes, and was about 48ft long, 10ft wide, and survived to over 9ft high. A small part of the structure had been uncovered by Time Team, who thought it was a great drain running down to the river. Unlike other abbey buildings whose foundations were extensively quarried, though, the latrine block was levelled, leaving the cesspit and its vaulted roof intact – presumably because its bricks were unpleasantly tainted.

Other abbey buildings
There is evidence for several buildings immediately to the west of the church that may be contemporary with the abbey. Strong candidates include the remains of at least one building (B8) in the courtyard of Syon House, comprising two areas of plain glazed tile floor: one was found during construction of the courtyard’s central pool, the other abutting an early brick wall beneath a flower bed nearby.
Syon House itself apparently incorporates parts of the abbey complex. This may explain why, during his remodelling of the interiors of the house in the 1760s, Robert Adam struggled with ‘some inequality in the levels on the old floors, some limitations from the situation of old walls’. Indeed, the truncated early brick walls and barrel vaults of a cellared building (B9), possibly at the end of the sisters’ putative west range, survive beneath the north wing of the house. The cellar also incorporates the stone wall that caused such a stir during the Time Team investigation. Its masonry would not have been out of place in the abbey, but it was not part of church’s north wall as originally proposed, for it was at least 4ft deeper and its north side was clearly intended to face the open space of a cellar and showed no sign of ever possessing a buttress.
Remnants of another apparently early stone wall (B10) survive beneath Syon House’s south wall, while the House’s west wing incorporates part of a vaulted undercroft (B11), commonly identified as a 15th-century abbey survival. The shell of the overlying entrance hall may also be substantially late medieval or early Tudor in date, concealed by the mid-18th-century Robert Adam interior and the early 19th-century Bath stone-clad exterior. This would accord with the discovery, during building work in 1824, of ‘two richly carved Gothic doorways’ in the west front of the house. Both are shown in a painting of the west front of Syon House thought to be of early 17th-century date.

Further west, the remains of ranges (B12-B16) surrounding quadrangular courts lie beneath the forecourt and lawn in front of Syon House. Some are betrayed by parch marks during spells of hot, dry weather, but all have been recorded by geophysical survey. The main southern and northern ranges (B12 and B13) are recorded in an inventory of 1593 and are depicted in the ‘17th-century’ painting with pitched red-tile roofs and small arched windows that would be in keeping with Bridgettine buildings, but look anachronistic when compared with Syon House. The painting shows the remnants of a wall adjoining the west end of B13, too, suggesting that part of the range had been demolished. We know that sections of these ranges were rebuilt in 1604-1606, and cartographic evidence suggests that B12 and B13 respectively survived until at least 1635 and the mid-18th century, though the other buildings in the group had gone by the 17th century.
The buildings around the western courts, including B11, possibly provided accommodation for important laity. More workaday ancillary buildings like the documented smithy, dairy, hoghouse, slaughterhouse, stable, and coal house, some of which would have been noisy and smelly, were probably located furthest from the church and accommodation. One such building may have been the so-called ‘Abbey Barn’ (B18), which appears on a map of 1607. Above ground, little of its original fabric has survived alterations and repairs over the intervening centuries, although an arched doorway of weathered Reigate stone can still be seen near the building’s south-east corner, and a small trench dug against its west wall in 2009 revealed foundations comprising successive courses of early stone masonry and brick.

Watery finds
Some 48 undated timber posts on the adjacent foreshore of the River Thames probably represent the waterfront of the abbey’s wharf. Although this is mentioned in 1492, and accounts for 1501-1502 indicate that it had a crane house, it was probably established decades earlier during the abbey’s construction, when large quantities of building materials were shipped to the site. A channel on the north side of the wharf, shown on an early 17th-century map extending back from the river towards Syon House, would have provided sheltered mooring for rivercraft, and was infilled in the mid-18th century.
The abbey enjoyed piped water for drinking and domestic purposes, conveyed through lead pipes from a conduit house nearly three-quarters of a mile to the west. The construction of this system would have been a substantial undertaking, and there can be little doubt the abbey waterworks were those later adapted for use by Syon House as sketched in a plan of 1600-1602 by the noted astronomer and mathematician Thomas Harriot, who was then living at Syon. The conduit house survived as a solitary building in farmland until the site was developed in 1933/1934, appearing on maps as a small oblong building probably only large enough to house a single collection tank. A drawing by the local historian George Bate shows that it was mainly of brick, with a doorway and small window of stone.
Epilogue
After Syon Abbey’s final closure, its community went into exile on the Continent, moving first to Flanders, then France, and finally Portugal, returning to England in 1861. With just three sisters remaining, their final convent near South Brent, Devon, closed in 2011, just four years short of their 600th anniversary. Archaeology has begun to shed light on their most famous home, but much remains to be done, for the sites of many documented abbey buildings have yet to be identified. The plan presented here is incomplete and contains much that is conjectural, but it does provide a model to be challenged, tested, and revised through further research.
Further reading
R Cowie (2020) ‘Syon Abbey: archaeological investigations at Syon Park, Brentford, 1997-2018’, Transactions of the London and Middlesex Archaeological Society 71: 107-202.
Source
Robert Cowie is an archaeologist who has worked with MOLA, Birkbeck (University of London), Time Team, and Richmond Archaeological Society to investigate Syon Abbey and its wider setting.