London’s Roman ruins are increasingly accessible – here’s where to see them

At some point in the 400s, a Saxon wandering in Roman Londinium’s ruins dropped his brooch on top of the fallen-in tiles of a decayed Billingsgate bath house. Whether he was scrabbling over the ruins or helping demolish them we will never know. But at any rate, no one ever bothered to tidy the tiles which remained as they had collapsed, with his brooch on top of them, until unearthed by archaeologists over a millennium later in 1969.

The Dark Ages in England were truly dark. In much of Europe, the end of the Roman Empire was less of a complete calamity than an ill-conceived changing of the guard. In France, most cities, towns and villages had a continuous existence, a history signified by place names and street patterns which can be traced back to their Roman origins.

In Britain, urban civilisation crumbled, and her streets and buildings crumbled with it. What few evidential shards of fifth-century construction survive are of blocked-in gates, ramparts repaired or of crude huts squatting in the ruins.

Yet over the last 80 years we have rediscovered Roman London in the city’s basements and sewers. Destruction has been the harbinger. First the Luftwaffe’s blitz, and now the ceaseless rush to replace the Victorian city with modernist glass lumps has unleashed the city’s archaeologists upon London’s substrata. Their discoveries can be visited in a growing number of basement museums which now form an ineluctable part of any visit to London, as important to understanding the city’s long story as St Paul’s.

The very heart of Roman civic life

The latest archaeological discovery is one of the most important. At 85 Gracechurch Street, besides the exuberant Victorian joy of Leadenhall Market (you’ve seen it in Harry Potter films), near where the medieval corn market was held, is a quietly elegant 1930s ‘Néo-Grec’ building whose temple-like door, giant order and spandrel panels give no clue that deep below, as has just been confirmed, are the remains of Roman London’s most important building, the Basilica: part law court, part town hall, part civic meeting place.

From earlier finds of the Roman Forum to the south, archaeologists had assumed that the Basilica was here, straddling Gracechurch Street. However, they had not dared hope that the ruins would be so substantial: one-metre-wide walls of flint, Kentish ragstone and Roman tile surrounding the very heart of Roman civic life, the so-called Tribunal where, on a raised dais, magistrates and officials met, adjudicated and opined.

On one unearthed tile, beside the maker’s stamp, they found the tile maker’s finger marks, the consequence of a careless moment two millennia ago, wood-fired and now preserved. The plans for the rebuilt 85 Gracechurch Street have been altered. In future you will be able to visit London’s Basilica in its basement.

Boudicca’s Layer

London is where London is because it is the last point before the sea where the Thames could be bridged. London was founded by AD 47, four brief years after Emperor Claudius’s invasion. It was scruffy, unfashionable and commercial. As Tacitus put it, London was “not distinguished by the title of colony yet exceedingly famous for its wealth of traders and commercial traffic”. London had started as it meant to continue, as a place to do business.

Like all ancient cities, Roman London suffered from periodic catastrophic fires, most infamously in AD 60 when the rebelling Queen Boudica put it to the torch and its inhabitants to the sword. There is little to see of her destruction today, but archaeologists consistently find a reddish-brown layer of ash beneath London, studded with scorched pieces of Roman pottery. They call it Boudicca’s Layer. Afterwards, in the 70s and 80s, London was rebuilt in ragstone and brick as well as timber with the full panoply of Roman civilisation: temples, baths, an amphitheatre and a basilica.

A place of worship

Descend from the new Bloomberg building into the reconstructed third-century Mithraeum, where Roman soldiers recited obscure catechisms. Examine the form of the building in its ghostly subterranean lighting. The Mithraic faith, with its eastern paraphernalia and bull-sacrifice, may seem a world away from modern Christianity, but the temple’s form with its three aisles, eastern apse and western narthex (or porch) is echoed in Roman and medieval churches. Entrance is free.

Other religious and ritual finds are even more obscure: metalwork thrown into the Walbrook and dogs and pots thrown into Southwark’s wells on the Thames’s southern shore.

A gracious bath house

From religion to relaxation. At one time or another, Roman London had at least 12 bath houses. The best preserved are in Billingsgate at Lower Thames Street, where that mysterious Saxon dropped his broach. Tucked away in a concrete tower block basement, accessed by utilitarian metal walkways, the hypocausts above which Roman Britons lay and sweated whilst slaves scraped the cleansing oils off their bodies still stand. You have to book in advance. It is only open on Saturdays from April to November. Tickets are £12 and £10 for children aged 14 or under (thecityofldn.com/directory/billingsgate-roman-house-and-baths).

The Roman wall

The later Roman London struggled with a debauched currency, inflation and the threat of Saxon raiders from the barbaric Germanic world. Around AD 200, London was given a city wall, later bolstered by bastions and extended along her river frontage. Some of Londinium’s Roman walls, extracted from the basements of blitzed Victorian buildings by post-war excavations, are still visible.

The best stretches are just north of the Tower of London (by Tower Hill tube station) and in Noble Street and Wallside where the Roman army had its fortress. The surviving segments are impressive, a very English mix of Roman and mediaeval rubble propped up by London stock bricks from Victorian foundations.

However they are a little melancholy besides modern glass behemoths or the Barbican’s concrete brutalism. If you don’t mind petrol fumes, there is more wall in the car park underneath the aptly named street, London Wall. The nearest tube is Barbican. The City of London also offers excellent tours with Dr Andrew Lane for £15.

The ancient wall partly survived Rome’s fall and was redeployed by Alfred the Great when he refounded Saxon London. Thus, the five initial gates (Ludgate, Newgate, Aldersgate, Bishopsgate and Aldgate) influenced the flow of medieval roads as they had their Roman predecessors. The main east-west Roman road ran from Newgate to the forum on Gracechurch Street.

London’s amphitheatre

In 1988, archaeologists digging beneath the courtyard in front of the medieval Guildhall found traces of London’s amphitheatre. Initially a timber structure with 10 to 15 tiers of wooden benches, it was rebuilt in the early second century of stone and tile.

It could seat an audience of around 5,000, possibly as much as a quarter of London’s second-century population. No visit to the city is complete without inspecting the remains beneath the Guildhall’s courtyard. Entrance is easy and free via the Guildhall Art gallery from ten till five, seven days a week.

Just possibly, the amphitheatre’s location, like those of the Roman wall’s gates, has also had a lingering influence on modern London’s geography. Historians have speculated that the abandoned amphitheatre, probably still visible as an enclosed depression in the ninth century, was a natural place to call a shire court or moot by which London’s new Wessex earls might collect taxes and maintain law, leading in turn to the siting of the Guildhall. If that is true, and we will never know for certain, then not only is London Roman coming back to us but it never really left.

Nicholas Boys Smith is the founding chairman of Create Streets. His history of London’s streets. No Free Parking is available from Bonnier books.