The Roman wall around London still decides where the City's roads run
Around AD 200 the Romans ringed Londinium with a stone wall two miles long. Most of it is gone, yet it still shapes the City of London: almost every modern road into the old walled area follows the route through one of its long-vanished gates.
The story begins with an earth bank and ditch around AD 100, then a garrison fort on the north-west side built between about 120 and 150, now called Cripplegate Fort. When the city-wide wall went up in the late 2nd or early 3rd century, two sides of the old fort, north and west, were made twice as tall and much thicker and folded into it, which is why the walled area has a distinctive corner in the north-west. Nobody knows exactly why such a costly defence was built. It may relate to Picts overrunning Hadrian's Wall in the 180s, or to the power struggle in which Britain's governor Clodius Albinus claimed the imperial throne, only to be defeated by Septimius Severus near Lyon in 197.
It was among the largest building projects in Roman Britain. Kentish ragstone was shipped by barge from quarries near Maidstone to raise a wall up to 6 metres tall and about 3 metres thick, enclosing some 130 hectares, fronted by a ditch 2 metres deep and with at least 22 towers along its eastern stretch. Gates at Ludgate, Newgate, Cripplegate, Bishopsgate and Aldgate lined up with the Roman road network; Aldersgate was added around 350 and Moorgate, first a minor side entrance, in the Middle Ages.
The river side stayed open for a long time, lined with timber wharves pushing into the Thames. After Saxon pirate raids in the late 3rd century, a riverside wall was begun in 280 and repaired around 390. Doubted for years, it was confirmed in 1977 when digs at the Tower of London showed a stretch of the Tower's inner curtain wall began as part of it.
Roman rule ended around 410 and the wall decayed, until restoration began, probably under Alfred the Great after 886. It marked the City's limits until late medieval growth blurred them. From the 18th century much of it, gates included, was torn down to ease traffic, and since the Second World War the remaining sections have been protected as scheduled monuments. A modern street also bears the name.
Source: London Wall
