The Thames was of great importance to Roman London. It was a 300-kilometre long highway to the west and the east, it brought drinking water for the town’s inhabitants and their animals, and it provided abundant fish and other seafood. Barges carried grain from upriver, while ships brought goods from other parts of the empire and sent exports in the other direction.
A key reason for where the Romans established Londinium was that a bridge could be built to allow a dry crossing over the Thames. Another was that the river was tidal up to that point, and perhaps as far as the modern-day Westminster. Its location opposite the mouth of the rivers Rhine and Scheldt, and the relatively short sea-crossing from the ports of Caletum (Calais) and Gesoriacum (Boulogne), ensured that most goods coming to Britannia were funnelled through Londinium. The sea journey from the Rhine estuary to Londinium was around 36 hours so, with turn-around time, a ship could make three or more voyages each fortnight.
Ships were swept up and down the river from the Thames Estuary to Londinium using the power of the tides. Without the tides it would have been tricky and arduous to navigate the winding river by wind and sail alone. Even so, it was unlikely that large vessels could reach Londinium. The sternpost rudder had not yet been invented and a ship’s 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 shifting sands of the Thames Estuary were treacherous, and it was probably also quite difficult to manoeuvre the larger ships through the wide bend that passed around the Isle of Dogs before reaching Londinium. Larger, sea-going ships were more likely to dock at Rutupiae (Richborough) or Dubris (Dover), the latter being the base of the local naval fleet, the Classis Britannica. Cargoes were then brought to and from there on smaller, flat-bottomed vessels capable of sitting on the foreshore at low tide. A variety of smaller vessels could ply up and down the Thames, to and from the coast or even across from the near-Continent.
The main port of Londinium was situated along the north bank of the river where wharves and warehouses were constructed. The Roman bridge over the river, built in 85-90AD, seems to have been in the same location as its medieval successor, that is with its northern end in line with Fish Street Hill, and was built of timber. It probably acted as a barrier past which only the smallest boats could pass, so coastal and sea-going ships loaded and unloaded immediately downstream of it.
There is little evidence of a formal harbour prior to the Boudicca revolt of 60AD, but writing some decades later, the Roman historian Tacitus looked back to Londinium immediately after the rebellion as “a colony much frequented by merchants and trading vessels”. We can probably assume, however, that the first quays were established from about 62AD, and the port continued to expand until the 3rd century.
From around 100AD and into modern times riparian owners have continuously advanced river walls in London further into the river. This had the effects of narrowing the channel and creating more quay-space. The advance of the quays in later centuries means that the original Roman harbour was not along the current riverbank but over 100 metres further north, under what is now Thames Street. However, the process of reclamation began during the Roman period, so the quays of the 3rd century in the central part of the city were further south than those of 150 years earlier.
During the 1st century the earliest Roman quays advanced the line of the waterfront by about 15 metres. The creation of the waterfront will have been a major enterprise and is unlikely to have been the work of an individual. It seems have been undertaken by the town authority, and archaeological discoveries indicate the involvement of the military.
To the west of the bridge a terrace was formed, held in place by a framework of braced timber baulks stacked horizontally on top of each other. This created a uniform frontage about two metres higher than the flood level, with a small jetty protruding into the river. Buildings, perhaps houses, warehouses or factories, were then constructed over this terrace. The waterfront west of the bridge initially extended to the mouth of the Walbrook stream, and beyond it by 200AD.
To the east of the bridge was a timber landing stage, nearly 60 metres in length east to west, constructed in 70AD. A braced timber wall faced onto the river but was not infilled and probably topped by timber decking. It was this section where ships moored to be loaded and unloaded. There were open-fronted warehouses along the quay, built of timber. The quays were lined with small warehouses for temporary storage. Some of the first buildings were later destroyed or badly damaged by fire and there was therefore occasional reconstruction of buildings. It is quite possible that the warehouses around the riverside were managed by the city’s authority. The quayside probably acted in part as a market, with some sales made directly from the vessels.
As the riverside moved southwards and new storage buildings erected along the new lines, former waterfront buildings were gradually transformed from commercial to residential use, somewhat similar to how 19th century warehouses in Docklands have been reused in modern times. Some of these buildings lasted for 300 years.