London Wall

Put your hand on the stone, if you can reach it. It is rough and grey, cool even on a warm day. Running through it, every so often, is a flat red stripe of tile. Around you, glass offices rise straight up, and the traffic hums along a road named after this very wall. You are touching the edge of Roman London, the line that once separated the city from everything beyond it.

The name London Wall belongs to two things at once. It is a busy modern street in the City of London. It is also the old defensive wall itself, whose broken fragments still appear across the Square Mile. The street follows the line of the northern stretch of that wall. So when you walk along it, you are tracing a boundary that Londoners have followed, in one way or another, for well over a thousand years.

To understand why the wall exists, go back to the Roman town of Londinium. The Romans founded it beside the Thames in the first century AD. Around AD 60, the town was burned during the revolt led by Boudica, the queen of the Iceni, a British tribe. Londinium recovered and grew into one of the most important towns in Roman Britain. But for a long time it had no complete wall around it at all.

The great city wall came later. Historians generally date it to the late second or early third century AD. Nobody knows exactly why it was built at that moment. Political instability in the empire is one common explanation. Civic pride may have played a part too. A wall said something about a city. It showed status and order, as well as strength.

Here is the first surprise. Some of the stone in front of you may have travelled a long way. The wall is built mainly of Kentish ragstone, a hard grey limestone from Kent, southeast of London. Workers carried it by barge along the Medway and the Thames. Archaeologists found the remains of a Roman boat near Blackfriars, still loaded with ragstone. It is a rare glimpse of the supply chain behind the wall.

Now look again at those red stripes. They are courses of flat Roman tile, laid at intervals through the stonework. They helped to level and bind the wall as it rose. They also make Roman work easy to recognise. Higher up, on some surviving sections, you may notice the stone change. Smaller, more irregular blocks often mark medieval repairs. Londoners kept patching and rebuilding this wall for centuries after the Romans left.

The complete circuit ran for roughly three kilometres. It curved from the river near the Tower of London, north and west around the city, and back down to the Thames. Outside it lay a defensive ditch. Its height is usually estimated at around six metres. For a traveller arriving on foot, the wall would have dominated the skyline. Entry came only through its gates.

And those gates are the second surprise, because their names are still here. Aldgate, Bishopsgate, Moorgate, Aldersgate, Newgate, Ludgate. Some were Roman in origin, and others were added in the Middle Ages. The gates themselves are long gone. Yet the names survive on streets, stations and street signs all around you. Every time a Londoner says Moorgate, they repeat the name of an opening in this wall.

There was also a fort. In the northwest corner of the Roman city stood a military fort, often called the Cripplegate fort. It was built earlier than the main city wall. When the city wall went up, its builders joined it onto the fort's existing walls. Parts of this corner survive near the street, close to the Barbican. Archaeologists only understood the fort properly in the twentieth century, after much of the area was cleared.

That clearing came through destruction. During the Second World War, bombing in the Blitz flattened large parts of this district. Buildings that had stood against the wall for generations were destroyed. In the rubble, long hidden sections of masonry came back into view. After the war, planners rebuilt the area with new roads, office towers and raised walkways. The modern street of London Wall was laid out as part of that rebuilding.

So the landscape you see today is a strange mix. Concrete and glass from the post-war decades sit beside stone that is nearly two thousand years old. Raised walkways pass overhead. In small gardens and cleared plots, sections of the old wall stand among lawns and trees. Look out for the stretch at Noble Street and the garden beside Saint Alphage. Look out too for the remains of rounded bastions, towers that were added to strengthen the wall.

The longest and most dramatic section is not on this street at all. It stands near Tower Hill, at the eastern end of the old circuit. There, a statue thought to represent the Roman emperor Trajan stands in front of the wall. The statue is a modern addition, not a Roman original. Even so, it is worth the short journey east to see how high the masonry still rises there.

As you move on, notice how often the old boundary still shapes the city. Streets bend where the wall once bent. Churches stand where gates once opened. The wall was largely pulled down from the eighteenth century, but its outline never really disappeared. Before you leave, look once more at that line of red tile in the grey stone. Then listen to the traffic, and walk on along a road that still follows the edge of Londinium.