At the end of the last Ice Age the world warmed and the glaciers melted. Large volumes of water flowed from Britain, south and east, through what is now the London area, which at times would have been completely submerged by a very wide river. The rising water level formed the English Channel, separating Britain from the Continent. The wide, slow-moving Thames deposited gravel at its edges. As it narrowed and became smaller over thousands of years, its gravel-depositing edges moved inwards in an ever-lower series of terraced banks, and thus the youngest layers lie closest to the current banks of the river and the oldest further away on the valley sides. Many rivers and streams flow into the Thames from the higher ground to the north and south and erosion from those during the past 50,000 years created the many valleys around which London was later built.

In 54 BC Julius Caesar led his army across the Channel to Britain to subdue the native Catuvellaunian tribe. Yet having beaten them back he decided there were more pressing issues and swiftly returned to Gaul. Back in Rome, he later recorded his campaign against the British ‘whose territories a river called the Thames separates from the maritime states at about eighty miles from the sea’. We therefore have the earliest record of the river, written long before the establishment of the city through which it now flows.

Tiberius, a strong military leader, secured the Roman Empire’s northern Continental borders. After his death the nobles who controlled the Senate in Rome became tired of their new young Emperor Caligula’s pleasure-seeking and longed for imperial glories such as the legendary exploits of Julius Caesar ninety years earlier. Caligula thus attempted an invasion of Britain in 40 AD but his troops, assembled at Boulogne, had other ideas, and it seems they threatened to mutiny. Britain, to the ordinary soldier, was a mysterious place at the far edge of the world, where boats carried the souls of their dead crews. The British were to be left alone for another three years.

Following the assassination of Caligula, his uncle, Emperor Claudius, felt the need to spread and reduce the power of the armed forces by sending 40,000 soldiers to the mysterious island, so the Romans finally arrived and conquered Britain. It took Commander Aulus Plautius and his troops a short while to actually find any Britons with which to engage but once located they were pursued across the Thames. Having taken the south-east corner of Britain, Plautius set up a ‘marching camp’, probably on the north bank of the river at Cornhill, waiting for the Emperor to arrive with reinforcements. Claudius came with a large reserve force, together with elephants (according to a later Roman account) that no doubt gave the natives a huge fright. The imperial army moved on to the main Catuvellaunian stronghold at Colchester, which the Romans took without too much difficulty. Claudius received oaths of loyalty there from eleven tribal kings and then returned home after just sixteen days, leaving his troops to set up the capital of the new Province of Britannia.

For the Emperor and so many troops to reach Colchester, as well as maintain supply lines back to Gaul, a bridge was required across the Thames. The first crossing was most likely a temporary pontoon structure put in place by army engineers. The Romans found the best location was just downriver from where the Thames was joined by the River Fleet. The banks of the Thames were quite marshy and the chosen site probably the most easterly, or downriver, point at which the river was sufficiently narrow, with solid land on either side.

When the Romans arrived, what is now central London was an area of small hills surrounded by marshy land that was often flooded by the incoming tides. The Thames was then the border between different warring tribes. The wider London hinterland, with its poor clay soil, remained forested and largely unpopulated, being far from each of the main tribal capitals. The thick forests and marshes on each bank made the river a natural barrier between the different groups of people that lived to its north and south but also a better means of transport and trade than overland.

Despite there being surprisingly little contemporary written evidence of the Roman city of Londinium, much has been pieced together by historians. There was a great deal of uniformity across the Empire, which allows an understanding of Londinium through discoveries made elsewhere. More locally, the remains of a Roman ship were discovered on the Thames in 1910 and two more in 1958 and 1962. After the Second World War many of the buildings in the City of London, particularly along the riverfront, were redeveloped and this gave the opportunity to delve below, before the replacement buildings were constructed. In the early 1970s a systematic programme of archaeology started and discoveries began to be made. Gradually, piece by piece, an understanding of the Roman Port of London emerged. Similarly, the existence of the Saxon town of Lundenwic was only revealed following excavations at Jubilee Market at Covent Garden in 1985.

The foundation and growth of Londinium

As the Romans established a new provincial capital at Colchester their forces moved northwards to continue the advance through Britain. In order to hold the areas they had conquered, one of their first priorities was to build wellengineered roads so that troops could move swiftly and have a means of supply. By the time they arrived in Britain the Romans were masters of rapidly building good roads and in the first years of occupation they constructed a network in the south east of Britain, partly based on native tracks that existed before their arrival.

A number of those roads connected at points to the north and south of the Thames bridge. The original temporary military crossing was probably soon replaced by a more permanent structure, thought to be located in line with the modern Fish Street Hill, slightly downstream of the current bridge. Such an important point required a military guard and a certain amount of management to supervise traffic and make repairs, so a small settlement was established on Cornhill. It soon became clear that a larger presence, formally constituted, was required on the site. The decision to build the new town of Londinium on the north side of the bridge was taken in around 47 AD and building works started the following year. A commercial district of shops and workshops evolved along the Via Decumana, the modern-day Cheapside. It quickly grew into a busy conurbation, home to people from all parts of the Empire but probably mostly from Gaul. The population increased rapidly and by 60 AD it is estimated to have been in the region of ten to twenty thousand people.

Londinium enjoyed a favourable location. A long navigable tideway brought vessels fifty miles from the North Sea, providing relatively easy access from Continental Europe. There was fresh water, fish stocks, and rich agricultural land further upriver. The first town lasted for little more than a decade before being destroyed and reduced to ash during Queen Boudicca’s rebellion. It had by then become an important and strategic place so had to be restored. Its destruction gave the Romans the opportunity to rebuild on a grander scale. During that same period a decision was taken that Londinium should become the capital of Britannia in place of Colchester. In the latter first century a vast basilica, the administrative centre, was constructed. Various government and public buildings were established, many in Kentish ragstone brought up the Thames by boat from a quarry near the River Medway. By the end of the century Londinium was beginning to look like the type of Roman town we would usually imagine. At some time between 85 and 90 AD a new bridge was built over the Thames, constructed of wood. The city continued to evolve and expand in the second century, particularly at the time of the visit of Emperor Hadrian in 122. Many public buildings were rebuilt for the occasion, including the amphitheatre, and a forum (marketplace) was created adjoining the basilica.

At some point during the period between 190 and 210 a semi-circular wall was constructed around the land-facing sides of Londinium. It was a massive undertaking, requiring around 1,300 barge-loads of ragstone from the Medway. It was not put up in haste, probably taking around two years to construct, and did not protect the vulnerable riverside, indicating that the city was not under immediate threat of attack. The existence of the wall thereafter created a barrier to further outward expansion of Londinium, which remained the case until the Middle Ages.

Initially many of the town’s daily requirements were imported but as time went on workshops were established to produce goods for the resident population. The remains of mills, slaughter houses, and a glassworks have been discovered as well as many tools for metal-working, carpentry, engineering, building and shipping. Britain was a major source of wool and it is most likely that the city was a centre of textile and leather industries.

The staple food of Roman times was cereals and bread, which depended on the seasonal harvests. Occasionally riots occurred in various parts of the Empire when availability was scarce and prices high, so each town arranged warehouses where grain could be stored in plentiful years. Londinium had the disadvantage of being surrounded by poor farmland so grain had to be transported lengthy distances, much of it arriving at the Thames quays by boat from Buckinghamshire, Oxfordshire and along the River Lea.

Fish was plentiful and could be caught in the river and estuary. Varieties included herring, cod, sprat, eel, carp and bass. Oysters were a staple diet of both the wealthy and working people. The largest oyster beds in Britain were in the Thames Estuary and the shellfish were either brought upriver live in barrels of sea-water or pickled and stored. Fish and shellfish were usually eaten with garum, a sauce made by boiling down whole fish until it became a paste, after which it could be stored in jars and sold in shops. A factory where it was made seems to have operated close to the Londinium waterfront. British oysters were exported to other parts of the Empire and their shells have been found in excavations of Rome. Salt was brought to Londinium from inland mines or by boat from around the coast, particularly from Essex where it was extracted from water using pans.

By the third century the population of Londinium is estimated to have been at least 50,000 and perhaps as much as a 100,000 people, a number that would not be achieved again until the fourteenth century.

The main Roman trade routes from the Mediterranean to Londinium

The port of Londinium

Even before Londinium had been established, the invading army created a supply base at Richborough in Kent, north of modern-day Sandwich, which in those days was a natural harbour. Its closeness to the coast of Gaul ensured that Richborough continued as a port throughout the Roman period, particularly for larger vessels from southern Europe. From the first until the late third centuries it was, along with Dover and Boulogne, a base of the Classis Britannica, the division of the Roman navy entrusted with the security of the English Channel.

Roman ships generally only sailed to Britain in the calmer weather of the summer months. The open sea was avoided whenever possible, with ships hugging the Continental coast until able to take the shortest possible route across the Channel. Goods from the Mediterranean were generally shipped to Britain via the inland Rhône-Rhine route, rather than around the more exposed Iberian Peninsula, and transhipped at Domburg in the Netherlands. From there the sea journey from the Rhine estuary to Londinium was around thirty-six hours so, with turn-around time, a ship could make three or more voyages each fortnight. An alternative route, particularly for goods originating in central Gaul, was along the Rhône and Loire rivers and up the west coast of Gaul.

Navigating up the Thames from the North Sea was always slow and difficult for sailing ships. First they had to negotiate the many sandbanks along the north and south shores of the Estuary, then wait for incoming tides to sweep them up to Londinium. The prevailing wind is more often westerly than from the east and thus the going could be slow as the crew tacked their way upstream along the winding river. It was therefore more convenient for goods arriving on larger vessels to be reloaded onto smaller vessels at Richborough. From there they were brought up the Thames to Londinium or transported by road.

In the first decade or two of the settlement of Londinium boats, were most likely berthed on a sloping prepared beach. The first attempts at establishing a harbour were probably not made until the rebuilding of the town following the Boudicca rebellion. In around 62 AD new timber quays and warehouses were constructed, perhaps at the same time as a new bridge. They included a landing stage for small vessels, parallel to the bank. The work was almost certainly a public, not private, initiative and probably undertaken or supervised by military engineers. To the west of the bridge the waterfront buildings seem to have been residential whereas those to the east formed commercial wharves. Quayside warehouses of timber may have been constructed in the first century and later replaced by others built in stone.

By the end of the first century the original quays and landing stage had been replaced. In those times the Thames was much wider than today, possibly as much as one kilometre across at Londinium, with marshy islands on the south bank that became submerged by high tides. The quays were built out into the river, gradually advancing the waterfront terrace by around fifty metres in various stages of development between the first and third centuries. This advancement would have provided berthing in deeper water for larger vessels.

Initially Londinium probably acted as a supply hub for Roman Britannia, with goods and equipment passing through for the military campaign and the first wave of Roman occupiers. As Londinium grew, other towns were also established, with over forty Roman coastal harbours known to have existed to which goods could be shipped. Food, manufactured goods and luxury items continued to be imported into the capital from all parts of the Empire but by the early second century produce arriving was simply to meet the daily needs of the city and its immediate hinterland. The harbour was to remain relatively small compared with the great ports of Portus and Ostia that served Rome.

Many goods landed at Londinium came from northern and central Gaul, the Rhine ports and Bordeaux, but there were also some from Spain and Mediterranean harbours and North Africa. Certainly sculptures, bronzes, household goods and foodstuffs that have been unearthed in Londinium were of Italian, Spanish or Mediterranean origin. Olive oil for cooking and lighting came from Spain, wine from Gaul, the Rhine and Moselle areas, Italy and Spain. Other imports included textiles, silk, linen, quernstones (millstones), timber, pottery, samian crockery, glassware, lamps, jewellery, fish, fruit, honey, grape-syrup and salt. Garum came from Gaul and Spain, at least until it was manufactured in Londinium. Most cargoes arriving from long distances would have been transhipped several times through the extensive Roman entrepôt network on their journey. Ragstone and other kinds of stone were quarried locally in Britain and shipped to Londinium by river or around the coast, as were locally produced ceramics and roofing slates in the second and third centuries. There is less information regarding exports from Londinium but they are known to include capes, rugs and lead ingots. Most likely other exports were wool, grain and slaves.

As is known from other parts of the Empire, goods were carried in sacks and barrels. Liquids, such as olive oil, were transported and stored in pottery storage vessels known as amphoras that could be stacked upright or horizontally. Unloading a Roman vessel was labour-intensive and, as it was seasonal work, probably required a casual workforce. It is possible that lifting mechanisms were used to unload larger items but there is so far little evidence. As boats arrived, some goods were probably sold directly to the public on the quayside while others were put into transit buildings or stored in warehouses.

Sea levels in the first century were about three to four metres lower than today. There is evidence that the Thames was then tidal perhaps as far upriver as Westminster, but may have gradually receded during the Roman period in one of the world’s slow cycles of climate change. If that is the case, vessels could no longer be swept up as far as Londinium on an incoming tide. That would be a significant factor in the decline of the city in the late Roman period.

Roman ships

When Julius Caesar’s fleet took part in a battle against the ships of the Veneti tribe of Brittany in 56 BC he noted how their vessels were better than his own for the conditions of the Atlantic coast. The Veneti ships had shallower keels that were more suited to tidal waters, solidly-built of oak, seams between planks caulked with moss, reeds or hazel shavings, with higher prows and sterns, and sails of leather that could withstand Atlantic storms. Thereafter Roman-era ships generally divided into either those of the Grecian/Roman tradition, suited to tideless Mediterranean conditions, or those for northern European seas based on Celtic designs. Goods arriving from the Mediterranean were generally transhipped several times throughout their journey, those ships arriving at Londinium would normally have been of the latter type.

Some Roman cargo ships are known to have carried loads of over 1,000 tons but it is unlikely that such large long-distance vessels ventured up the Thames. Those to be found in Londinium were more likely to be either smaller round-bottomed river and coastal boats, which were unable to beach at low tide and therefore anchored in mid-stream to load and unload, or flat-bottomed barges.

Importation and exportation was a precarious business, with large investment in the vessel and its cargo, financial risk and high reward. Much of the cost was raised in the form of syndicates of wealthy men who would not be ruined in the event of a ship being lost at sea. At first, cargo ships arriving were owned by traders from other parts of the Empire but there is evidence of later shipbuilding at Londinium, which indicates ownership by locally-based traders.

A typical Roman ship or barge was propelled by a single sail, mounted towards the front of the vessel. The centralized sternpost rudder had not yet been invented and thus direction was achieved by a large oar protruding from the right-hand side of the stern – the steer-board or ‘starboard’ side of the boat – or oar rudders on each side.

The decline of the Roman Empire

Roman civilisation reached its zenith during the mid-first century, at around the same time that Londinium was being established. While the city matured and grew on the western extremity of the Empire through the second and third centuries it was protected, and occasionally prospered, from troubles in Rome and elsewhere.

During the 170s victorious troops arriving back from battles in the east carried with them a plague that had a devastating effect on the Roman people. It wiped out about 5 million people, perhaps between 10 and 25 per cent of the entire population of the Empire. Garrison towns were particularly affected by the plague, leaving the Empire’s border vulnerable. At around the same time, the Langobardians invaded from Northern Germany, causing a war that lasted for seventeen years, during which they captured areas as far south as northern Italy; the first time Italian soil had been occupied for three centuries. A peace treaty was signed in 181 and the border was restored along the line of the River Danube but it was clear to the northern barbarians from that time on that Rome was not invincible.

To the north of the Continental Empire new nations formed, with the Goths, Franks and Alamanni becoming a major threat in the third century. The Franks, based in the lower Rhineland areas, began making raids on the wealthy and vulnerable east coast of Britain and the Thames estuary, while inland agricultural areas prospered and large mansions were built. People of wealth abandoned the coasts of East Anglia, the Thames Estuary, Kent, the south and the Severn Estuary, where they were vulnerable from raids by the Franks or Irish. A significant factor was the disbanding of the Classis Britannica fleet in the late third century. Long-distance voyages in and out of Londinium were unlikely to have been affected but coastal shipping was probably in greater danger. By the mid-third century the population of Londinium had reduced, as had the amount of imports arriving. As Londinium declined in importance and fewer ships arrived and departed, the timber quays and jetties along the river began to decay, probably from around 250 AD. Riverside warehouses were converted for residential use as trade diminished.

Londinium went into a long, slow decline during the fourth century. It had become successful partly because it was the most convenient port from which to trade with the Rhineland and near Continent. As the Roman armies lost control of the northern Continental areas it became safer to ship goods to and from Boulogne to the ports on the south coast of Britain. By the end of the fourth century Venta Belgarum (Winchester) overtook Londinium as Britain’s leading commercial centre.

When the east coast of Britannia came under attack from Germanic raiders a riverside wall was built to complete the enclosure of Londinium. Unlike the first three sides, the riverside section was certainly erected in haste and with far less care taken in its construction, using whatever materials were to hand. We can therefore be sure that it was constructed when the city was under immediate threat of attack. With the town almost cut off from the river by the wall, the timber quays had largely been dismantled by the fourth century. Despite its defensive wall, Londinium was overrun in 367 by an alliance of Picts, Irish, Franks and Saxons and had to be retaken by Roman forces.

In the early fifth century Visigoths invaded the Italian peninsula. Rome no longer had the ability to defend Britannia and the province became independent from what remained of the Empire. The population of southern England had been shifting more to the West Country and Londinium gradually dwindled until, at the end of the fifth century, it was most probably largely deserted. For a period of time life continued in Britain as it had done previously, with the Romano-British choosing their own leaders and prospering. In order to repel attacks by Picts from the north they enlisted Saxon men from the area around the mouth of the River Elbe in what is now northern Germany, as well as Jutes and Angles. The Romano-British began to squabble amongst themselves, however. During the first half of the fifth century the immigrant fighters rebelled against their Romano-British paymasters, slaughtering many of their leaders in about 459. In the following decades England was gradually divided into a number of tribal kingdoms.

The site of Lundenwic, showing the locations of the modern-day Covent Garden, Trafalgar Square and Charing Cross Station.

Some of the ports known to have traded with Lundenwic.

The Saxon port of Lundenwic

When Londinium was abandoned, the Thames and its tributaries continued to be used for carrying and communication. The early Saxons were seafarers and did not possess the knowledge of how to maintain roads to a Roman standard. Yet they also initially lacked the skills to build sophisticated ships, and even their largest vessels were designed to be pulled up onto a beach.

Saxons began to berth their boats at low tide on the sloping foreshore two miles to the west of the deserted Londinium, where the river suddenly swings southwards in a large curve near the modern-day Charing Cross station. A new community known as Lundenwic began to grow there from the mid-seventh century. From a simple start of pulling boats onto the sloping bank, a market and trading port developed in the area of modern-day Covent Garden. ‘Wic’ was the Saxon word for market, indicating that Lundenwic developed for the purpose of trading, and is still remembered in the modern street name of Aldwych (‘old market’). At the early stages in the life of the community there was no need for shops, stalls, warehouses or quays. Traders could arrive from along the river or around the coast, moor up and, as the tide went out, allow the boat to berth on the muddy bank, selling goods directly from the vessel. Evidence indicates that a planned town grew rapidly in the 670s, which would be during the reign of the Mercian king Wulfhere. From the late seventh century a wooden embankment was constructed along and out into the river, perhaps with jetties.

Many artefacts of the time have been discovered around Covent Garden and therefore the limits of the settlement of Lundenwic can be defined. The line of the north shore was about 100 metres south of, and roughly parallel to, the old Roman road that was still in use. (By the late twelfth century the road was known as the Strand, Germanic for bank or shore). Lundenwic stretched from there northwards to around where the street Shorts Gardens now runs. The east side was approximately along Kingsway, stretching westwards to Trafalgar Square, a distance of over a kilometre. Its centre is now the site of the Royal Opera House. Within that area a permanent community developed, living in small wooden homes. The population consisted of farmers and smallholders, fishermen, traders and craftsmen dealing in bone, antler, metal and cloth. On the town’s fringes were gravel pits and horticulture, with some farms between Lundenwic and Thorney Island (modern Westminster) further along the river, including one at modern-day Downing Street. Northwards, towards the Roman road of Holborn/New Oxford Street, there was boggy ground.

The early Saxon period was an age when any form of transport other than boats was rare, with very few people owning a horse and cart. As a result, beach markets developed at locations along the river at Woolwich, Greenwich, Twickenham and Hampton Wick. Other port markets that developed around the same time included Sandwich, Hamwich (Southampton) and Gipeswic (Ipswich).

There is a written reference from around 672, in a grant by Frithuwold, sub-king of Surrey: ‘by the port of London, where ships come to land, on the same river [the Thames] on the southern side of the public way [the Strand].’ The historian Bede wrote in the early eighth century of a Frisian trader buying a Northumbrian slave at Lundenwic back in 679. In 731 he described London as ‘an emporium of many nations who come to it by land and sea’.

Saxon period trading markets existed by royal charter, with revenue collected by port-reeves on behalf of the king or landowner in the form of tolls on boats that berthed to trade. Extant documents from around 680 state the trade regulations to be observed by the men of Kent when they bartered at Lundenwic. At that time King Hlothere of Kent appointed a royal official, or reeve, to administer local wics and by at least the 730s the kingdom of Kent was levying tolls on boats using the market of Lundenwic. A document dated 734 refers to ‘the remission of all dues … which are exacted by the tax-gatherers in the port of London’ and from that time the king gave the bishops of Rochester and Worcester and the abbess of Minster in Thanet the right to levy tolls on certain ships at the port.

The lack of exotic items found in excavations shows that during the early stages of the development of Lundenwic, from around 630 until the mid-eighth century, trade was quite local in its nature. Most goods brought to the beach market were perhaps produce from further along the river or nearby coastal villages. The inhabitants probably survived mainly on grain, meat, hay, timber and wool from the immediate hinterland. Local farmers visited the market from up and down the river to buy and sell produce, arriving in small punts that were dug out from the trunk of a tree, between two and four metres in length. They were sufficient to carry up to about four people or several animal carcasses and were propelled by a pole or paddle. Long distance traders arrived in ships made from oak planks of between 20 and 30 metres in length, powered by a sail and steered by an oar, probably of clinker construction. Excavated fishbones and shells include freshwater species, as well as marine varieties such as cod, haddock, herring, whiting, bass, plaice, flounder, whale and oysters.

Money was required in order to easily buy and sell goods. Seventh century gold coins known as thrymsas have been found at other places bearing the name ‘LONDVNIV’, showing that a mint had already been established. During the late eighth century silver penny coins were being minted for the Mercian kings bearing the name ‘LUNDINIA’.

By the eighth century the population of Lundenwic had grown in size and goods were being traded with ports such as Gipeswic, Eorforwic (York) and Hamwic. The greatest international trade was with settlements around the mouth of the Rhine and the north-west coast of what is now France, and Lundenwic was frequented by Frisian and Frankish traders. Ships sailed to and from the ports of Dorestad (Wijk-bii-Duurstede in the Netherlands), Sliaswich (Schleswig in Germany), Quentovic (near Boulogne), and even as far as Norway. Wine, quernstones, pottery and luxury goods were imported and ships returned with wool or cloth. Dried figs and grapes indicate trade with places even further afield.

Lundenwic was a relatively large community of perhaps six to seven thousand people by its heyday in the mid-eighth century, by then within the kingdom of Mercia on the border with Essex. Excavations show a settlement at that time of around sixty hectares, laid out in a grid pattern, similar to earlier Roman towns. Although never as large as the old Roman city, it was nevertheless probably the largest Saxon settlement in England. On several occasions, between 764 and 801, the town suffered from fires from which it may never have fully recovered. It went into decline during a period of unrest in the Carolingian kingdoms in France and Germany in the late eighth century, suffered from rivalry between the Saxon kingdoms of Wessex and Mercia, and the added threat of attack from Vikings from the early ninth century. Lundenwic, like its Roman predecessor, was thereafter abandoned by the Saxons, having flourished for less than a century.