Founding Unlike many cities of Roman Britain, Londinium was not placed on the site of a native settlement or
oppidum. Prior to the arrival of the
Roman legions, the area was almost certainly lightly rolling open countryside traversed by
numerous streams now underground.
Ptolemy lists it as one of the cities of the
Cantiaci, but
Durovernum (Roman
Canterbury) was their
tribal capital (). It is possible that the town was preceded by a short-lived Roman military camp, but the evidence is limited and this topic remains a matter of debate. Archaeologist
Lacey Wallace notes "Because no
LPRIA (Late Pre-Roman Iron Age) settlements or significant domestic refuse have been found in London, despite extensive archaeological excavation, arguments for a purely Roman foundation of London are now common and uncontroversial." The city's Latin name seems to have derived from an originally Brittonic one and significant pre-Roman finds in the Thames, especially the
Battersea Shield (
Chelsea Bridge, perhaps 4th-century BC) and the
Wandsworth Shield (perhaps 1st-century BC), both assumed to be
votive offerings deposited a couple of miles upstream of Londinium, suggest the general area was busy and significant. It has been suggested that the area was where several territories intersected. There was probably a
ford in that part of the river; other Roman and
Celtic finds suggest this was perhaps where the opposed crossing
Julius Caesar describes
in 54 BC took place. Londinium expanded around the point on the River Thames narrow enough for the construction of a
Roman bridge but still deep enough to handle the era's seagoing ships. Its placement on the
Tideway permitted easier access for ships sailing upstream. but archaeological excavations undertaken since the 1970s by the Department of Urban Archaeology at the
Museum of London (now
MOLAS) have suggested the early settlement was largely the product of
private enterprise. A timber drain by the side of the main
Roman road excavated at
No 1 Poultry has been dated by
dendrochronology to 47 AD. The roads are now known by
Welsh or
Old English names, as their original Roman names have been lost because of the lack of written and inscribed sources. (It was customary elsewhere to name roads after the
emperor during whose principate they were completed, but the number and vicinity of routes completed during the time of Claudius would seem to have made this impractical in Britain's case.) The road from the Kentish ports of
Rutupiae (
Richborough),
Dubris (
Dover), and
Lemanis (
Lympne) via
Durovernum (
Canterbury) seems to have first crossed the Thames at a natural ford near
Westminster before being diverted north to the new bridge at London. The Romans enabled the road to cross the marshy terrain without
subsidence by laying down substrates of one to three layers of oak logs. This route, now known as
Watling Street, passed through the town from the bridgehead in a straight line to reconnect with its northern extension towards
Viroconium (
Wroxeter) and the legionary base at
Deva Victrix (
Chester). The
Great Road ran northeast across
Old Ford to
Camulodunum (
Colchester) and thence northeast along
Pye Road to
Venta Icenorum (
Caistor St Edmund).
Ermine Street ran north from the city to
Lindum (
Lincoln) and
Eboracum (
York). The
Devil's Highway connected Londinium to
Calleva (
Silchester) and its roads to points west over
the bridges near modern
Staines. A minor road led southwest to the city's main cemetery and the old routes to the ford at Westminster.
Stane Street to
Noviomagus (
Chichester) did not reach Londinium proper but ran from the bridgehead in the southern suburb at
Southwark. These roads varied from wide. or may have assisted the Romans against his tribesmen during that revolt. His will had divided his wealth and lands between Rome and his two daughters, but
Roman law forbade female inheritance and it had become common practice to treat allied kingdoms as life estates that were annexed upon the ruler's death, as had occurred in
Bithynia and
Galatia.
Roman financiers including
Seneca called in all the king's outstanding loans at once and
the provincial procurator confiscated the property of both the king and his nobles.
Tacitus records that when the king's wife
Boudica objected, the Romans flogged her, raped her two daughters, and enslaved their nobles and kinsmen. Boudica then led
a failed revolt against Roman rule. Two hundred ill-equipped men were sent to defend the provincial capital and Roman colony at Camulodunum, probably from the garrison at Londinium. The Iceni and their allies overwhelmed them and razed the city. The
9th Legion under
Quintus Petillius Cerialis, coming south from the
Fosse Way, was
ambushed and annihilated. The procurator
Catus Decianus, meanwhile, escaped with his treasure to
Gaul, probably via Londinium.
1st century , depicting the first
bridge over the
River Thames, shown as having been of largely wooden construction After the sack of the city by Boudica and her defeat, a large military fort covering 15,000 m2 was built at
Plantation Place on
Cornhill, with 3m-high banks and enclosed by 3m deep double ditches. It was built as an emergency solution to protect Londinium's important trade and to help reconstruct the city. It dominated the town and lay over the main road into Londinium controlling traffic from
London Bridge and on the river. Several major building projects at this time such as roads, a new quay and a water lifting machine indicate the army had a key role in reconstruction. The fort was in use for less than 10 years. The city was eventually rebuilt as a
planned Roman town, its streets generally adhering to a grid skewed by major roads passing from the bridgehead and by changes in alignment produced by crossings over the local streams. It recovered after about a decade. The first
forum was constructed in the 70s or 80s Forums elsewhere typically had a civic temple constructed within the enclosed market area; British sites usually did not, instead placing a smaller shrine for Roman services somewhere within the basilica. The first forum in Londinium seems to have had a full temple, but placed outside just west of the forum. By the turn of the century, Londinium was perhaps as large as 60,000 people and had replaced
Camulodunum (Colchester) as the provincial capital. A large building discovered near
Cannon Street Station has had its foundation dated to this era and is assumed to have been the governor's palace. It boasted a garden, pools, and several large halls, some of which were decorated with
mosaic floors. It stood on the east bank of the now-covered
River Walbrook, near where it joins the Thames. The
London Stone may originally have been part of the palace's main entrance. Another site dating to this era is the
bathhouse () at
Huggin Hill, which remained in use prior to its demolition around the year 200.
Brothels were legal but taxed. In 2025 ruins of oldest Roman basilica in London were found. It was constructed between 78 and 84 A.D.)
Port A large port complex on both banks near London Bridge was discovered during the 1980s. The bulk of the Roman port was quickly rebuilt after Boudicca's rebellion when the waterfront was extended with gravel to permit a sturdy wharf to be built perpendicular to the shore. The port was built in four sections, starting upstream of the London Bridge and working down towards the Walbrook at the centre of Londinium. Expansion of the flourishing port continued into the 3rd century. Scraps of
armour, leather straps, and military stamps on building timbers suggest that the site was constructed by the city's
legionaries. Major imports included
fine pottery, jewellery and
wine. at the
Museum of London During the early 2nd century, Londinium was at its height, having recovered from the fire and again had between 45,000 and 60,000 inhabitants around 140, with many more stone houses and public buildings erected. Some areas were tightly packed with
townhouses (). The town had piped water and a "fairly-sophisticated" drainage system. The governor's palace was rebuilt, the marketplace rivalled those in Rome and was the largest in the north before
Augusta Treverorum (
Trier, Germany) became an imperial capital. floor from Londinium (
British Museum) By the second half of the 2nd century, Londinium had many large, well-equipped stone buildings, some of which were richly adorned with wall paintings and floor mosaics, and had subfloor
hypocausts. The
Roman house at Billingsgate was built next to the waterfront and had its own bath. Londinium seems to have shrunk in both size and population in the second half of the 2nd century. The cause is uncertain, but plague is considered likely, as the
Antonine Plague is recorded decimating other areas of Western Europe between 165 and 190. The end of imperial expansion in Britain after Hadrian's decision to build
his wall may have also damaged the city's economy. Although Londinium remained important for the rest of the Roman period, no further expansion occurred. Londinium remained well populated, as archaeologists have found that much of the city after this date was covered in
dark earth which accumulated relatively undisturbed over centuries.
London Wall behind
Tower Hill tube station. A line of Roman red-brick tiles can be seen near its base. Some time between 190 and 225, the Romans built the London Wall, a defensive
ragstone wall around the landward side of the city. Along with Hadrian's Wall and the road network, the London Wall was one of the largest construction projects carried out in Roman Britain. The wall was originally about long, high, and thick. Its dry moat () was about deep and wide. In the 19th century,
Charles Roach Smith estimated its length from the Tower west to Ludgate at about one mile () and its breadth from the northern wall to the bank of the Thames at around half that. In addition to small pedestrian
postern gates like the one by
Tower Hill, it had four main gates:
Bishopsgate and
Aldgate in the northeast at the
roads to Eboracum (
York) and
to Camulodunum (
Colchester) and
Newgate and
Ludgate in the west along at the road that divided for travel
to Viroconium (
Wroxeter) and
to Calleva (
Silchester) and at another road that ran along the Thames to the city's main cemetery and the old ford at
Westminster. The wall partially utilised the army's existing fort, strengthening its outer wall with a second course of stone to match the rest of the course. Others link it with
Clodius Albinus, the British governor who attempted to
usurp Septimius Severus in the 190s. The wall survived another 1,600 years and still roughly defines the City of London's perimeter. In 2023 a section of the wall at the City Wall at Vine Street Museum opened to the public.
3rd century depicting
Mithras killing the
bull, discovered in the ruins of the
London Mithraeum Septimius Severus defeated Albinus in 197 and shortly afterwards divided the province of Britain into
Upper and
Lower halves, with the former controlled by a new governor in
Eboracum (
York). Despite the smaller administrative area, the economic stimulus provided by the wall and by Septimius Severus's campaigns in
Caledonia somewhat revived London's fortunes in the early 3rd century. The northwest fort was abandoned and dismantled when it was erected on the east bank at the head of navigation on the
River Walbrook about from the Thames.
Riverside wall From about 255 onwards, raiding by
Saxon pirates led to the construction of a riverside wall. It ran roughly along the course of present-day
Thames Street, which roughly formed the shoreline. Large collapsed sections of this wall were excavated at
Blackfriars and the Tower in the 1970s.
Temple of Isis An inscription found on a third-century stone altar recorded the rebuilding of a
temple of
Isis by the governor of
Britannia Superior –
Marcus Martiannius Pulcher. An earlier inscription found on a first-century
flagon suggests that a temple of Isis had existed much earlier. The Egyptian goddess was believed to have influence over the sea and hence the safety of seafarers.
Carausian Revolt coin from his mint at Londinium showing a woman kneeling in front of a Roman soldier at the city walls, thanking him for bringing
Allectus's rule to an end In 286, the emperor
Maximian issued a death sentence against
Carausius, admiral of the
Roman navy's
Britannic fleet (
Classis Britannica), on charges of having abetted
Frankish and Saxon piracy and of having embezzled recovered treasure. Carausius responded by consolidating his allies and territory and revolting. After fending off Maximian's first assault in 288, he declared a new
Britannic Empire and issued coins to that effect.
Constantius Chlorus's sack of his Gallic base at
Gesoriacum (
Boulogne), however, led his treasurer
Allectus to assassinate and replace him. In 296, Chlorus mounted an invasion of Britain that prompted Allectus's Frankish mercenaries to sack Londinium. They were only stopped by the arrival of a flotilla of Roman warships on the Thames, which slaughtered the survivors. The event was commemorated by the golden
Arras Medallion, Chlorus on one side and on the other a woman kneeling at the city wall welcoming a mounted Roman soldier. Another memorial to the return of Londinium to Roman control was the construction of a new set of forum baths around 300. The structures were modest enough that they were previously identified as parts of the forum and market but are now recognised as elaborate and luxurious baths including a with two southern pools and an eastern
swimming pool.
4th century Following the revolt, the
Diocletian Reforms saw the British administration restructured. Londinium is universally supposed to have been the capital of one of them, but it remains unclear where the new provinces were, whether there were initially three or four in total, and whether
Valentia represented a fifth province or a renaming of an older one. In the 12th century,
Gerald of Wales listed "Londonia" as the capital of
Flavia, having had
Britannia Prima (
Wales) and
Secunda (
Kent) severed from the territory of Upper Britain. Modern scholars more often list Londinium as the capital of
Maxima Caesariensis on the assumption that the presence of the
diocesan vicar in London would have required its provincial governor to outrank the others. The governor's palace The possible existence of the shrine room is supported by 19th-century excavations under
Gracechurch Street, immediately adjacent to the church's eastern end. These unearthed an adjoining room covered in yellow panels with a black border, 'with a tessellated floor, suggesting it may have had a higher status than normal, possibly acting as an antechamber for the aedes or shrine-room'. The alignment of the church is close to the lines of the basilica, being off by just two degrees, and it is feasible for the understructure to have utilized the dry solid 2nd century basilica wall fabric for support. If St Peter's was built in the Roman era, it would make the church contemporaneous to the potential Romano-British church at
Silchester, similarly built adjacent to the Roman Basilica and most likely pre-
Constantine in age. London certainly had a Christian community in 314 when Bishop Restitutus attended the Council of Arles. This community must have had some meeting place, and apart from St Peter's no other location has yet been proposed, either in antiquity or in the modern era. There is, however, some conflicting evidence to the theory that St Peter's was deliberately sited above a pagan shrine room. Current research suggests it was very rare for early English Christian churches to be founded in pagan temples and that when temples were turned into churches, this occurred later, in the late 6th century and onwards. This was also true elsewhere in the Roman Empire; for example in Rome. By this time the former associations of the sites had probably died down. There is more evidence that early English Christian churches met in private homes and that some Roman villas also converted rooms to dedicated places of Christian worship. In 1995 a large and ornate 4th-century building on
Tower Hill was discovered: built sometime between 350 and 400, it seems to have mimicked
St Ambrose's
cathedral in the imperial capital at
Milan on a still-larger scale. It was probably dedicated to St Paul. From 340 onwards, northern Britain was repeatedly attacked by
Picts and
Gaels. In 360, a large-scale attack forced Emperor
Julian to send troops to deal with the problem. Large efforts were made to improve Londinium's defences around the same time. At least 22
semi-circular towers were added to the city walls to provide platforms for
ballistae and the present state of the river wall suggests hurried repair work around this time. It may have been at this point that one of the existing provinces was renamed Valentia, although the account of Theodosius's actions describes it as a province recovered from the enemy. In 382, Emperor
Magnus Maximus organised all of the British-based troops and attempted to establish himself as western emperor. The event was obviously important to the Britons, as "Macsen Wledig" would remain a major figure in
Welsh folklore, and several
medieval Welsh dynasties claimed descent from him. He was probably responsible for London's new church in the 370s or 380s. its large church on Tower Hill burnt to the ground. Over the next century,
Angles, Saxons,
Jutes, and
Frisians arrived and established tribal areas and kingdoms. The area of the Roman city was administered as part of the
Kingdom of the East Saxons – Essex, although the Saxon settlement of
Lundenwic was not within the Roman walls but to the west in
Aldwych. It was not until the
Viking invasions of England that King
Alfred the Great moved the settlement back within the safety of the Roman walls, which gave it the name
Lundenburh. The foundations of the river wall, however, were undermined over time and had completely collapsed by the 11th century. Memory of the earlier settlement survived: it is generally identified as the ''''
counted among the 28 cities of Britain included in the History of the Britons'' traditionally attributed to
Nennius. == Demographics ==