In 1066 William the Conqueror defeated the English army at the battle of Hastings and Norman forces advanced west into Worcestershire.
To reinforce their occupation, the Normans built a motte and bailey castle on the south side of the city, taking advantage of the shape of the existing burh walls.
The remaining burh walls continued to be used into the Norman period, but the city had already spread beyond them, reducing their effectiveness.

During the Anarchy (1135–1153) rival factions of King Stephen and the Empress Matilda contested the kingdom and Worcestershire proved to be a key battleground.
The first attack on Worcester itself occurred in late 1139 when an Angevin army from Gloucestershire assaulted the city.
After an attempt to take the castle on the south side of the city, the Gloucester forces entered from the north, looting and burning.
Worcester became a base for Stephen's forces for a period, before joining the Empress's faction.
In response, Stephen first stormed and burnt the city in 1148, and then attacked it again in 1150, shortly before the end of the conflict.
From the accounts of these sieges, it appears that Worcester still lacked substantial walls during this period.

In the second half of the 12th century a new city wall began to be built around Worcester, with work probably continuing until early the next century.
Enclosing about 85 acres (34.4 hectares), its design tracked the flow of natural streams to the north and east, and made use of the castle in the south as part of the defences.
The walls were constructed of sandstone, and appear to have been surrounded by a flat bottomed, water-filled ditch, more than 30 feet (9 m) wide.
The new walls cut across existing parts of the city and would have required the demolition of numerous existing buildings that lay in their way; the new defences also cut off the outlying districts of Sidbury, Lowesmoore, Foregate Street and The Tything from the inside of the walled city.
Three main gates were built in the walls – North Gate, St Martin's Gate and Sidbury Gate – protected by gatehouses of paired circular towers and arrowslits for use by crossbowmen.
Smaller gates were built between them, such as Friar's Gate.

Civil war broke out again in England in 1215 between forces loyal to King John and rebel barons, supported in due course by Prince Louis of France, in what gas become known as the First Barons' War.
Worcester sided with the rebels, and in July 1216 the city was attacked by forces under the command of Ranulf, the Earl of Chester.
Ranulf attempted to storm the castle, rather than the north side of the city, and after he eventually gained access a £100 fine was imposed on the city with the threat that their walls would be destroyed if the money was not paid.
 Although Worcester's walls clearly played a military role during this period, they would also have been symbolically important to the city and have played a part in controlling civic access and enforcing the city's laws.

One method of paying for the construction and maintenance of city walls was a tax called murage, usually levied by permission of the king on particular goods being imported into a city.
In Worcester, murage was raised to support work on the walls during three main phases,  1224 to 1239, 1252 to 1310 and 1364 to 1411.
Worcester was attacked again during the Second Barons' War in the 1260s, and the records suggest that some of the murage payments were used to repair damage caused by that attack.
In the late 14th century a watergate was built in the western walls of the city, close to a slipway for launching boats.
Worcester's last murage grant occurred in 1439, although in 1459 Henry VI allowed the city to use stones from the castle to repair the walls to defend the city in anticipation of a Yorkist attack during the Wars of the Roses.
As in many other English towns and cities, as the medieval period progressed, housing began to encroach on the city walls in Worcester.
In 1066 William the Conqueror defeated the English army at the battle of Hastings and Norman forces advanced west into Worcestershire. To reinforce their occupation, the Normans built a motte and bailey castle on the south side of the city, taking advantage of the shape of the existing burh walls. The remaining burh walls continued to be used into the Norman period, but the city had already spread beyond them, reducing their effectiveness.
During the Anarchy (1135–1153) rival factions of King Stephen and the Empress Matilda contested the kingdom and Worcestershire proved to be a key battleground. The first attack on Worcester itself occurred in late 1139 when an Angevin army from Gloucestershire assaulted the city. After an attempt to take the castle on the south side of the city, the Gloucester forces entered from the north, looting and burning. Worcester became a base for Stephen's forces for a period, before joining the Empress's faction. In response, Stephen first stormed and burnt the city in 1148, and then attacked it again in 1150, shortly before the end of the conflict. From the accounts of these sieges, it appears that Worcester still lacked substantial walls during this period.
In the second half of the 12th century a new city wall began to be built around Worcester, with work probably continuing until early the next century. Enclosing about 85 acres (34.4 hectares), its design tracked the flow of natural streams to the north and east, and made use of the castle in the south as part of the defences. The walls were constructed of sandstone, and appear to have been surrounded by a flat bottomed, water-filled ditch, more than 30 feet (9 m) wide. The new walls cut across existing parts of the city and would have required the demolition of numerous existing buildings that lay in their way; the new defences also cut off the outlying districts of Sidbury, Lowesmoore, Foregate Street and The Tything from the inside of the walled city. Three main gates were built in the walls – North Gate, St Martin's Gate and Sidbury Gate – protected by gatehouses of paired circular towers and arrowslits for use by crossbowmen. Smaller gates were built between them, such as Friar's Gate.
Civil war broke out again in England in 1215 between forces loyal to King John and rebel barons, supported in due course by Prince Louis of France, in what gas become known as the First Barons' War. Worcester sided with the rebels, and in July 1216 the city was attacked by forces under the command of Ranulf, the Earl of Chester. Ranulf attempted to storm the castle, rather than the north side of the city, and after he eventually gained access a £100 fine was imposed on the city with the threat that their walls would be destroyed if the money was not paid.  Although Worcester's walls clearly played a military role during this period, they would also have been symbolically important to the city and have played a part in controlling civic access and enforcing the city's laws.
One method of paying for the construction and maintenance of city walls was a tax called murage, usually levied by permission of the king on particular goods being imported into a city. In Worcester, murage was raised to support work on the walls during three main phases,  1224 to 1239, 1252 to 1310 and 1364 to 1411. Worcester was attacked again during the Second Barons' War in the 1260s, and the records suggest that some of the murage payments were used to repair damage caused by that attack. In the late 14th century a watergate was built in the western walls of the city, close to a slipway for launching boats. Worcester's last murage grant occurred in 1439, although in 1459 Henry VI allowed the city to use stones from the castle to repair the walls to defend the city in anticipation of a Yorkist attack during the Wars of the Roses. As in many other English towns and cities, as the medieval period progressed, housing began to encroach on the city walls in Worcester.
Worcester city walls