Fortress Londinium: Tracing London’s Roman defences

This summer, a museum displaying a portion of the wall that once encircled Roman London has opened, and three sections of the settlement’s riverside defences have been granted scheduled status. Carly Hilts visited the museum and spoke to Jane Sidell to learn more about Londonium’s fortifications.


Founded soon after Claudius’ conquest of AD 43, Roman London – Londinium to its inhabitants –quickly flourished into a commercial powerhouse: a Thames-side trade centre so resilient that (a writing tablet of AD 62 attests; see CA 317) it was up and running again just a year or two after the devastation of the Boudican revolt. Having risen from the ashes, the settlement continued to thrive, and in around AD 195-225 its status was literally set in stone, thanks to the construction of towering walls that not only enhanced its defences but also made a triumphant and highly visible statement of civic pride.

Over recent decades, excavations within the City of London have uncovered surviving remains of the long-vanished riverside wall that once completed the circuit of the capital’s Roman defences, as well as evidence of Roman and medieval wharves and docklands. Photo: MOLA

Running for around 2.5 miles and enclosing an area of some 330 acres, the walls were punctuated by four city gates (today known as Ludgate, Newgate, Bishopsgate, and Aldgate), together with another entrance linked to the fortress at Cripplegate that had stood in the area since AD 125-150. They originally embraced Londinium on three sides only, with the waters of the Thames completing the circuit, but in the 3rd century an additional riverside wall filled the gap. This was a drastic step, speaking of a need to enhance the town’s defences that was so urgent that it overcame commercial concerns – the new construction effectively severed the settlement’s all-important access to the river, and to the wharves and dockyards that had played such a key role in its mercantile success.

Come the 4th century and the threat of Saxon raids prompted further enhancement: mighty bastions rose up against the outer edge of the landward wall. These constructions – and the effort and resources that would have gone into creating them – speak of the importance of maintaining London’s fortifications, and the walls continued to be a defining feature of the medieval period, being repeatedly repaired and rebuilt over the centuries. As the city expanded, however, the old defences were gradually overwhelmed by the evolving urban environment.

Above: One of the best-known sections of London’s landward wall stands outside Tower Hill underground station. It is accompanied by a sculpture of the Emperor Trajan, and a replica of a memorial – shown in the adjacent modern wall, and (Below) in more detail – commemorating Gaius Julius Alpinus Classicianus, the procurator who rebuilt London after the Boudican revolt. His tombstone had been reused in the construction of a nearby bastion, and is now displayed in the British Museum.
Photos: C Hilts

Most of the riverside wall in particular has fallen victim to the march of modernity, with its line lying beneath what are now Upper and Lower Thames Street, once the river’s north foreshore (which lay 100m further inland than today). However, sections of this wall are known to still survive underground (of which, more below), and portions of the landward wall stand today – though not always in the most obvious locations.

As the ground level today is so much higher than it was in the Roman period, many of these ‘above-ground’ survivors seem subterranean to modern observers. One such example is a stretch of wall preserved in an underground car park close to the former site of the Museum of London – a striking juxtaposition of old and new. Enjoying rather more picturesque surroundings is its near-neighbour, which forms the southern border of a sunken space called Salters’ Garden. Perhaps the most prominent portion, however, stands directly outside Tower Hill underground station, opposite the rather later fortifications of the Tower of London. Looming over onlookers, its Roman material survives to a height of 4.4m, surmounted by medieval stonework that boosted its stature to 10.6m. Like the rest of the Roman defences, its facing blocks of Kentish ragstone sandwich a core of rubble and mortar, and are layered with red bands which were used to ensure that courses remained level for long distances, and to increase stability.

Displaying the wall

About five minutes’ walk from the Tower Hill section of wall, this portion of the Roman defences is displayed in the newly opened museum The City Wall at Vine Street. It had become incorporated into a 19th-century building, and supports that were added during its excavation in 1905 and 1979 have been preserved as part of its story. Photo: Urbanest

Just five minutes’ walk from Tower Hill, another stretch of wall has become the focus of a new museum that provides a vivid insight into how one part of London has changed over the centuries. Called The City Wall at Vine Street, the museum has been delivered by student accommodation providers, Urbanest, alongside partners Historic England, the City of London Corporation, and the Museum of London. Its dominating feature is the wall itself: an imposing edifice of Roman masonry standing up to 3m high above its plinth, butting up against a chunk of 20th-century brickwork and supported by black-painted bricks, concrete, grey steel props, and red steel jacks. This initially visually jarring composition provides a fascinating summary of the later history of the wall, representing its discovery and its preservation over the course of the last century. This part of the wall survived to the present day thanks to it being hidden in plain sight – it became a shared wall between an office building and a closed-down nightclub, and only now can both sides be viewed at the same time.

The wall’s western face was rediscovered in 1905, during the construction of the (appropriately named) Roman Wall House, and was preserved in the building’s lower ground floor – the black-painted bricks and concrete slab on which they sit date to this period. When Roman Wall House was pulled down ahead of the construction of Emperor House in 1979, Museum of London archaeologists carefully removed layers of modern plaster to reveal the wall’s eastern face. The steel props and jacks date from this time, adding another layer of the wall’s history.

Projecting from the eastern face of the wall are the remains of Bastion 4a, the only Roman bastion that can be seen in London. 
A reconstruction of how the wall and bastion may have looked, based on drawings by Chris Green and Graham Evernden with the London Museum. Photos: Urbanest

Historic England Inspectors have been monitoring the scheduled monument, and were actively involved in discussions for redisplay as part of redevelopment since 2010. After acquiring the site in April 2016, Urbanest worked in close collaboration with the City of London Corporation and Historic England to incorporate the wall into the design of the new development to ensure that it is visible and can be enjoyed by the public. This is not the only piece of Roman masonry included within the displays, however. The 1979 works also uncovered the remains of a previously unknown defensive tower: Bastion 4a. This was once a mighty construction, extending 5.4m from the eastern face of the wall, with foundations stepped into the backfill of the original wall ditch to ensure its stability. Within its make-up, archaeologists found that Roman builders had incorporated recycled tombstones – probably scavenged from an extramural cemetery known to exist just to the east of the site.

The bastion is significant as it is the only Roman example that can be seen in London: while other tall towers still stand in plain sight alongside wall remains – including near the old Museum of London site – these were rebuilt in the medieval period. Yet, while its cousins were reused and reconstructed over the years, Bastion 4a seems to have fallen out of use by the 13th century. It is not known whether it was deliberately demolished or collapsed before its materials were recycled elsewhere, but today only its foundations remain to testify to its once impressive dimensions.

Rise, fall, and rebirth

Alongside the wall remains in the museum, display cases feature a diverse range of artefacts, lent and curated by the Museum of London, which were recovered during excavations on the site. They mainly represent rubbish dumped into the ditch that ran alongside the wall, and this everyday detritus paints a vivid picture of the area’s Roman occupants and those who followed in subsequent centuries. Some of these objects provide tantalisingly tangible links to the individuals who called this part of London home: take, for example, the fragments of clay roof tiles where you can still see lines drawn by the potter who made them, sweeping a finger across the surface of the tiles while they were still wet. It is not known what these marks mean – perhaps some kind of signature, or a note of quality or quantity, the display captions suggest – but they are joined by a rather more informal equivalent: a tile bearing the paw print of a cat who wandered across the drying tiles, no doubt to the chagrin of their maker.

The wall remains are accompanied by displays of artefacts spanning the Roman period to the present day, reflecting how the site was used over the centuries. Photos: C.Hilts

Other Roman finds testify to the presence of reasonably high-status buildings in the area: hints of elegant floors decorated with plain mosaics and highly polished opus signinum; fragments of hollow blocks from hypocaust heating systems; scraps of painted wall plaster. These are accompanied by fragments of amphorae used to transport and store exotic delicacies from across the empire, such as olives, wine, olive oil, and fish sauce. Roman London was, like the modern city, a melting pot of different cultures, with people and goods travelling through the important port from across the province and the wider empire – tiny traces of their everyday experiences are reflected by the presence of such personal and domestic items as pieces of mortaria used for food preparation, a delicate bone hairpin, and a colourful array of pottery sherds in snaking patterns through the displays.

Perhaps the most evocative finds, though, are a simple series of low denomination coins, tarnished and tiny, that were found at the foot of the wall. Mostly dating from the late 3rd to mid-4th century, when the fortifications would have long been a familiar feature of the London landscape, they might have been dropped by soldiers patrolling the defences, or by people living in their shadow. As the accompanying caption notes, they have probably been touched by more Roman Londoners than any other object included in the museum.

Roman artefacts on display include stonework from the wall and bastion; a diverse range of pottery sherds; and a series of later Roman coins. Photo: C. Hilts

Londinium’s prosperity was not to last, however, and after the official framework of Roman authority withdrew from Britain c.AD 410, the city was gradually abandoned and reclaimed by nature. The walls that had safeguarded the settlement for so long crumbled into rugged ruins that were rapidly rewilded by invasive plants and small creatures like the snails whose shells are used in the displays to represent the settlement’s decline. By the 7th century, a new Anglo-Saxon settlement had sprung up about a mile to the west of the deserted Roman streets – known as Lundenwic, it occupied the area now called Aldwych (‘the old trading site’), north of the Strand, and in this incarnation London blossomed once more – but while its success drew merchants back along the Thames to ply their wares, it also attracted Viking raiders eager to plunder its new-found wealth. In the late 9th century, Alfred the Great led his people back inside the protection of the Roman walls, refortifying them and dubbing the resurrected town ‘Lundenburh’. Thereafter, the city walls would once again form the focus of settlement, literally shaping London’s destiny as the medieval town grew within them.

On the site of the museum itself, people continued to dump their rubbish into the wall ditch. Butchered animal bone is displayed alongside pieces of jugs and bowls spanning AD 1100-1500, as well as other items that demonstrate medieval fashions and the city’s continued close links to the Continent. As well as colourful glazed fragments of pottery that were made locally but reflect French styles, we see pieces of unglazed pottery speckled with crushed shell – a technique employed throughout Roman and medieval London. Together, they show the twin streams of continuity and change that run through the settlement’s early history.

Urban industry

By the 1500s, the ditch had been filled in, but signs of high-status dwellings reoccur in this period. They include floor tiles imported from what is now Belgium – plain, but a distinct step up from the earthen floors of humbler homes of this time – that may have been associated with a convent that was built over the nearby Roman cemetery.

This was home to the Minoresses of St Clare without Aldgate, a community of Franciscan nuns living an enclosed life in an abbey located just outside the city wall. They were members of the Order of St Clare, also known as the ‘Poor Clares’ in English, which was founded by one of St Francis of Assisi’s earliest followers. Franciscan monks often called themselves fratres minores, ‘lesser brothers’ as a sign of humility, and this was often rendered simply as ‘Minors’ by the English-speaking laity. The female equivalent was sorores minores, and the Poor Clares were accordingly nicknamed ‘Minoresses’. Their name is still preserved in the area’s modern name, Minories.

From the Tudor period we also see a distinctive green-glazed stove tile. It was imported from Germany, as were the many characterful Bartmann jugs depicting bearded male figures, some grinning jovially, some with downturned grimaces, some complete, some reduced to fragments, which have been found in quantity on the Vine Street site.

Butchered animal bones, ceramic roof tiles, and a range of pottery fragments help to illuminate everyday life beside the Roman defences. Photo: C. Hilts

The Bartmann jugs were made in Frechen, as was a fragmentary brown stoneware vessel displayed alongside them, decorated with a scene of dancing villagers – a later 16th-century motif known as Das Bauernfest, ‘the peasant festival’. Finally, German fashions are reflected, too, by a colourful blue-and-white stoneware jug from Westerwald: dating to the mid-16th to mid-17th century, it would have originally been topped with a hinged metal lid, today represented only by two holes in the handle.

It was not just Continental tastes that were popular in 16th- and 17th-century London, however. The whiteness of Chinese porcelain was also greatly admired, and English artisans strove to mimic its colour through chemical means. Tin-glazing – coating clay with tin-lead oxide to create a brilliant white, with other metal oxides applied to make contrasting colours – became a major industry in post-medieval Southwark and Lambeth, but some Londoners had access to the genuine articles too. The Vine Street displays include a bowl with a blue dragon motif – the colours are rather subdued, suggesting that it was a cheap product made for the export market, but it was clearly a prized possession, only discarded when it was a century old.

By now, the wall was no longer a boundary – London had long since expanded beyond it, and the Vine Street section was surrounded by a bustling array of workshops, yards, and industries including metal-working, glassmaking, and bell-casting. The city was again part of an expanding empire with goods and people arriving from all over the world – some of them not of their own will, as London was a key hub in the Triangular Trade that transported sugar, spirits, and enslaved people between Europe, Africa, and the Americas. Since most of the ivory arriving into Britain at this time came from Africa, it is possible that the ivory-working waste found on the Vine Street site reflects this trade; as might some of the finished products on display, including a knife-handle and a double-sided comb whose design has little altered since the Roman period: another hint of continuity amidst change.

The site’s commercial fortunes were transformed when Fenchurch Street Station was built a few minutes away in 1841, linking the Aldgate area to the docks and ushering in a flood of goods that needed warehouses to store them. One such building was the Metropolitan Bonded Warehouse, which was built on the site in 1863. The Roman wall was absorbed into this structure, plastered over and hidden in plain sight, enduring in obscurity even as the building suffered severe bomb damage in 1941 – until it was brought to light again by archaeologists in 1979.

Down by the Riverside

For those visiting the new museum, there are a number of other sites within easy reach where Roman remains can be seen in situ. They include the Temple of Mithras, which is displayed in a purpose-built structure off Cannon Street (CA 334), and the remains of the Roman amphitheatre, preserved beneath the Guildhall (CA 137, 109, and 331). A small private bathing suite known as the Billingsgate Baths (CA 333) can also be visited on pre-booked tours; the latter remains are tucked away beneath a building on Lower Thames Street, near the line of the Roman riverside wall.

Three sections of this latter wall have just been granted scheduled status, recognising their significance as historic monuments. While the river wall cannot be seen above ground, elements were excavated in the 1970s and 1980s (CA 79), and more recently in MOLA investigations between 2006 and 2016. To-date, waterside wall remains have been observed at eight sites, though only half still survive in situ. One of these is at the Tower of London, and the other three are those that were recently granted protected status. They are described in detail in Historic England’s National Heritage List for England (see ‘Further information’ on p.43), but we will summarise their main features here.

One of Londinium’s four gates (Aldgate) stood moments away from the new City Wall museum, where Jewry Street meets Aldgate High Street. 
Photos: C.Hilts

The first of the newly scheduled sections was uncovered at Riverbank House on Upper Thames Street. Surviving for over 20m in length and standing up to 1.4m high, its construction is strikingly similar to its landward cousin, standing on a stone plinth and made of Kentish ragstone surrounding a flint core. Just as significantly, though, it was accompanied by well-preserved Roman timbers testifying to the thriving Thames-side commercial buildings that occupied the foreshore before the wall was constructed. When the site was partly excavated in 1981-1982, a sequence of five Roman waterfronts was uncovered, beginning in the 2nd century with the construction of a substantial quay built of squared baulks arranged in six tiers. There was also a mid-2nd-century dockside building with a wall measuring nearly 3m long and 0.6m wide, built of flint and Kentish ragstone – it was later truncated by the construction of the riverside wall, which bit into its northern end. The quayside was reinforced in the late 2nd century with a post-and-plank revetment, after which the early 3rd century saw the construction of an open-fronted landing stage and, towards the end of the century, another revetment and quay.

MOLA’s excavations in 2008-2009 added to this picture, opening 22 trenches around the perimeter of the site; as well as documenting further Roman dockside features, they uncovered echoes of the site’s later life, including part of a late 11th- or early 12th-century building, and a succession of medieval waterfronts and associated structures spanning the early 12th to 15th century. Contemporary documents allow us to identify some of the industries that these buildings served: in the 13th and 14th centuries, this tenement was home to brewhouses, dyehouses, a workhouse, and wharves.

Above and below: Remains of the riverside wall at Riverbank House.
Photos: MOLA

Over at Three Quays – a site that was partly excavated in the 1990s, with more substantial investigations in 2010-2012 (prompted by the demolition of an office building and the construction of an apartment block). There, the riverside wall survived only as the chalk raft on timber piles that has been observed beneath all excavated sections of the wall, providing a sturdy foundation in its waterlogged environment. Other Roman features included at least seven riverside structures, including horizontal beams set on piled foundations, representing a quay running for about 35m. This was replaced in the mid-2nd century by another, larger quay whose baulks survive up to 2m high and were found to go 8m deep. It was extended to both the west and east in the later 2nd century, and the site was still evolving in the early 3rd century, with another revetment added in AD 215.

It is in the medieval period that the site really came into its own, however, with a succession of at least 36 quayside buildings, revetments, and other reinforcements. These include three structures dating to 1130-1240, which incorporated recycled clinker boat boards; a series of four post-and-plank revetments running through the mid-13th century; a flurry of 14 quayside structures in 1270-1350; and walls dating to the 14th, 17th, and 18th centuries.

A well-preserved array of Roman and medieval quayside structures. Photo: MOLA

The final stretch of wall was uncovered at Sugar Quay, where another 45m of riverside wall has been recorded, made of monumental stone blocks measuring 60cm by 50cm by 35cm. It had been built over a box quay made of thick stacked oak beams, dated to AD 133, and excavations on the site in 1973 and 2013-2016 have uncovered a busy array of Roman waterfront structures and revetments spanning the late 1st to 3rd century. The site was also home to diverse medieval riverside features from the 12th century, and mainly reflecting a period when this part of the foreshore was occupied by the late-13th-century Wool Wharf and Stone Wharf.

All the newly scheduled features have been preserved in situ, and while they are less visible than the remains now displayed on Vine Street, they represent powerful memorials to the people of Londinium and the bustling commercial landscape that they once knew.

Further information 
- The City Wall at Vine Street is open 9am-6pm daily; entry is free but timed tickets must be pre-booked; see for more details.
- To read more about the Riverbank House, Sugar Quay, and Three Quays stretches of riverside wall, search for 1484161, 1484183, and 1484184 respectively at https://historicengland. - Dr Jane Sidell is Inspector of Ancient Monuments at Historic England.