In 1338 Southampton was raided by French forces; the town's defences proved inadequate, particularly along the quays on the west and south of the city.

With the advent of gunpowder weapons in the 1360s and 1370s, Southampton was one of the first towns in England to install the new technology to existing fortifications and to build new towers specifically to house cannon.

This process continued into the early 20th century until, in the post-war years, the walls were recognised as an important historical feature of Southampton.

It was an important trading port and a defensive outpost for the town of Winchester, located on the site of Bitterne Manor, today a suburb of modern Southampton.

By the time that the Normans conquered England in 1066, the town of Southampton occupied a rectangular area overlooking the mouth of the River Test, an important medieval waterway.

[4] The Normans built a castle within the town on the site of a probable large English hall, and considerable damage was caused to the surrounding local buildings as space was opened up for the new fortification.

[7] Following the threat of French invasion in the 1170s, Henry II invested modest additional resources in the castle, but no efforts were undertaken to improve the town's ditches and banks.

[11] Stone houses, often combining accommodation and storage facilities, began to be built in Southampton by the wealthiest merchants, particularly in the prosperous western and southern parts of the town, but these properties could not be easily defended against attack.

[12] The English Channel was contested militarily between England and France during the 13th century, and Southampton was both an important base for naval operations and a tempting target for raiders.

[17] There appears to have been little interest in defending the west and south quays, however, probably because doing so would have hampered Southampton's merchants when they moved their trading goods in and out of the town.

[20] Later investigations by the Crown would suggest that some of the monies raised in these murage grants had been misspent, however, contributing to the poor standard of town defences, which included large gaps in the walled circuit.

[22] Edward III responded to the raid by taking immediate steps to shore up Southampton's defences and ordering the town to be fully enclosed by stone walls.

In 1339 the sheriff conscripted workmen and specialists to improve the defences, and money to pay for the building materials was raised by commuting the prison sentence of a senior official in Southampton to a fine.

[23] The enquiry also concluded that the outer doors and ground floor windows of properties facing the sea should be filled in to form a more defensible line.

Around 1378 to 1379 the ongoing French threat led to gunports for handguns being built into the western Arcade wall, and by 1382 the town bought its own gun.

[32][nb 4] Concerns increased significantly after the invasion scare of 1457, when French troops successfully attacked the town of Sandwich on the south coast.

[39] A town gunner had also been appointed by the 15th century, earning the highest salary of any local official and was responsible for maintaining the guns and manufacturing gunpowder.

[37] As late as the mid-16th century, additional improved rectangular gunports, similar to those on the Device Forts along the Channel, were added to the West Gate by the quays.

South Gate formed the main administrative centre for the port during the period, housing the Clerk of the King's Ships and collecting customs revenue.

[51] The walls fared better than Southampton Castle, which was sold off to property speculators in 1618, but they played no part in the English Civil War.

[58] The urban growth of Southampton, as in many English walled towns and cities, put considerable pressure on the older fortifications.

In 1898 to 1899, for example, parts of the wall west of Biddles Gate, including a square tower, were demolished to create the Western Esplanade road.

[63] Around half the length of the 2 km (1.25-mile) long medieval town walls still survives in the 21st century, mainly on the north and west sides of Southampton, together with 13 of the 29 defensive towers and six out of the eight gates.

This is architecturally important as it was one of the first urban buildings to be built to hold gunpowder artillery – in this respect, it closely resembles Cow Tower in Norwich.

[71] The Bargate remains an elaborate building, taking military symbolism and combining it with rich civic heraldry and decoration above the gateway.

[74] The Arcades form part of the surviving west walls and are a unique feature in England; their closest architectural equivalent are in Rouen, France.