What was the wall for?

The construction of such a monumental structure was a substantial investment of resources by the residents of Londinium. An estimated 35,000 cubic metres of Kentish ragstone was quarried 70 miles away, near Maidstone, and then shipped via the Medway and Thames to London. The route of the wall would have been cleared of buildings, the ground levelled, and rivers and streams canalised before construction began.

The wall’s form and design demonstrate a lack of urgency, rather than a response to an impending military threat. In places its route ran well beyond the occupied urban area, and the masonry was completed to a high standard, suggesting that speed was not a priority.

Initially the wall only covered the landward sides of the city – a significant omission if it was designed to protect against assault. Walls were also being built around towns and cities elsewhere in the Roman empire during this period of relative peace. Many of the important towns of Roman Britain, such as Camulodunum (Colchester), built similar stone walls, suggesting that they were expressions of wealth and status rather than a response to a threat.

In Londinium, the result was an impressive barrier, defining its boundaries and marking it out to visitors as the most important city in Roman Britain.

The medieval wall

The Romans had abandoned Londinium by about AD 450. The Saxon settlement of Lundenwic was established further west, near the area known as The Strand today, and the area within the wall remained largely unoccupied.

In 886 King Alfred reoccupied the city in response to Viking raids along the Thames, and it’s likely that the walls were repaired at this time. They survived to be an important feature of the city at the time of the Norman Conquest of 1066.

Large parts of the Roman wall were incorporated into the medieval defences of the city, which mostly followed the same line. London’s medieval wall rose over 10 metres high, and had extra gates. In about 1300 a new postern gateway – a side gate large enough for pedestrians – was built through the wall immediately south of the Tower Hill section. Watches were kept at the gates, and the guard was often strengthened in response to potential threats to the city, such as rebellions and wars.

The city’s citizens were held financially accountable for the wall, paying ‘murage’ to keep it in good condition. The walls and ditch were a heavy maintenance burden, but they were generally well kept until the English Civil War (1642–51).

Visiting the wall today

The section of wall preserved at Tower Hill shows not only its imposing height in the medieval period, but also its Roman origins. At 10.7 metres above present ground level, it is one of the tallest surviving parts of the circuit. The upper portions and many of the facing stones are medieval, but the lower 4 metres are easily identified as originally Roman by the characteristic horizontal bands of red tiles.

A copy of the inscription from the monument to the Roman procurator Classicianus, found in the bastion north of this section of wall, is displayed in the concrete wall nearby, close to where it was found. The monument itself is in the British Museum. The statue that welcomes visitors is a copy of a Roman statue believed to be of the emperor Trajan (r. 98–117), who pre-dated the wall.

The medieval postern gate sits at the south end of the underpass leading to the Tower of London. Just to the north of the Tower Hill section, a further lengthy section of the wall can be seen at Cooper’s Row.