The London Wall was the defensive wall first built by the Romans around Londinium, their strategically important port town on the River Thames in what is now London, England, and subsequently maintained until the 18th century.
It is now the name of a road in the City of London running along part of the course of the old wall between Wormwood Street and the Rotunda junction where St. Martin’s Le Grand meets Aldersgate Street. Until the later Middle Ages, the wall defined the boundaries of the City of London.
Although the exact reason for the wall’s construction is unknown, the wall appears to have been built in the late 2nd or early 3rd century. This was around 80 years after the construction in 120 AD of the city’s fort, whose north and west walls were thickened and doubled in height to form part of the new city wall. It continued to be developed until at least the end of the 4th century, making it among the last major building projects undertaken by the Romans before the Roman departure from Britain in 410 . The length and size of the wall made it one of the biggest construction projects in Roman Britain. The completed wall, which had gateways, towers and defensive ditches, was built from Kentishragstone. It was 3.2 km long enclosing an area of about 130 ha. It was 3 m wide and up to 6 m high.
With the collapse of the Western Roman Empire, Londinium ceased to be the capital of Britannia . From around 500, an Anglo-Saxon settlement known as Lundenwic developed in the same area slightly to the west of the old abandoned Roman city. But by about 680, London had revived sufficiently to become a major Saxon port. However, the upkeep of the wall was not maintained and London fell victim to two successful Viking assaults in 851 and 886 AD . The city walls of London were repaired as the city slowly grew until about 950 when urban activity increased dramatically.
By the 11th century, London was beyond all comparison the largest town in England . The size and importance of London led to the redevelopment of the city’s defences. During the early medieval period – following the Norman Conquest of England – the walls underwent substantial work that included crenellations, additional gates and further towers and bastions. Aside from the seven City Wall gates and the four bars, there are the 13 water-gates on the Thames where goods were unloaded from ships.
During the Great Fire of London in September 1666, almost all of the medieval City of London inside the wall was destroyed. The seven gates to the City of London, with many repairs and rebuilding over the years, stood until they were all demolished between 1760 and 1767. Work to demolish the walls continued into the 19th century; however, large sections of the wall were incorporated into other structures. Some of the noticeable ruins in the bomb-damaged City during the Blitz in the Second World War were remnants of London’s city wall.
All that remains of the wall are a few sections, some of which can be seen in the grounds of the Museum of London, in the Barbican Estate and around Tower Hill.
And here you can see a lot of the remains :