Norwich Castle is a medieval royal fortification in the city of Norwich, in the English county of Norfolk. William the Conqueror (1066–1087) ordered its construction in the aftermath of the Norman Conquest of England. The castle was used as a gaol from 1220 to 1887. In 1894, the Norwich Museum moved to Norwich Castle. The museum and art gallery holds significant objects from the region, especially works of art, archaeological finds and natural history specimens.

The historic national importance of the Norwich Castle site was recognised in 1915 with its listing as a scheduled monument. The castle buildings, including the keep, attached gothic style gatehouse and former prison wings, were given Grade I listed building status in 1954. The castle is one of the city's twelve heritage sites, and is managed by the Norfolk Museums Service.

The interior of the keep was reconstructed over five years to how it would have looked in the early 12th century, fully reopening in August 2025.

History

thumb|left|Plan of Norwich Castle keep by [[William Wilkins (1751–1815)|William Wilkins, prior to alterations completed in 1793 by John Soane]]

Norwich Castle was founded by William the Conqueror some time between 1066 and 1075 and originally took the form of a motte and bailey. Early in 1067, William embarked on a campaign to subjugate East Anglia, and according to military historian R. Allen Brown it was probably around this time that the castle was founded. The earliest recorded incident at the castle is in 1075, when it was besieged by troops loyal to William to put down a rebellion known as the Revolt of the Earls, co-led by Ralph de Gael, Earl of Norfolk. Ralph went abroad to try and rally support from the Danes leaving his wife Emma in charge of the garrison. The support failed to materialise and the rebellion was put down. The siege lasted three months and ended when Emma secured promises that she and her garrison would be unharmed and given safe passage out of the country.

Norwich is one of 48 castles mentioned in the Domesday Survey of 1086. Estimates suggest that between 17 and 113 houses were destroyed in the building of the castle. Excavations in the late 1970s discovered that the castle bailey was built over a Saxon cemetery. The historian Robert Liddiard remarks that "to glance at the urban landscape of Norwich, Durham or Lincoln is to be forcibly reminded of the impact of the Norman invasion". Until the construction of Orford Castle in the mid-12th century under Henry II, Norwich was the only major royal castle in East Anglia.

By about 1100, the motte had been made higher and the surrounding ditch deepened. The stone keep, which stands today, was built on the south west part of the motte between 1094 and 1121. The keep internally had two floors. The entrance was to the upper floor on the eastern side, accessed via an external stone stairway to a forebuilding which became known as Bigod Tower. An area of land surrounding the castle, known as the Castle Fee was immediately brought under royal control, probably for defensive purposes.

During the Revolt of 1173–1174, in which Henry II's sons rebelled and started a civil war, Norwich Castle was put in a state of readiness. Hugh Bigod, 1st Earl of Norfolk, one of the more powerful earls, joined the revolt against Henry. Bigod landed 318 Flemish soldiers in England in May 1174 and with 500 of his own men advanced on and captured Norwich Castle. Fourteen prisoners were held for ransom. When peace was restored later that year, Norwich was returned to royal control.

The castle provided sanctuary to Jews fleeing the violence that erupted against them across East Anglia in Lent 1190, and which reached Norwich on 6 February (Shrove Tuesday). Those Jews unable to find safety inside the castle were massacred.

The Pipe Rolls, records of royal expenditure, note that repairs were carried out at the castle in 1156–1158 and 1204–1205. <span class="anchor" id="Thomas de Burgh">Thomas de Burgh</span> ( , ; – ?), younger brother of William de Burgh, Lord of Connacht and Hubert de Burgh, Earl of Kent, and older brother of Geoffrey de Burgh, Bishop of Ely, became the castellan in 1215.

The castle as a prison

Parts of Norwich castle were used as a prison from an early stage; a gaol was made in the castle which serviced the wider county. State prisoners were confined in this gaol in 1264 and 1274. Sometimes the earl in charge of a royal castle refused to allow the sheriff to imprison convicted criminals therein, even though it had been customary to do so.thumb|South-west view of the castle: watercolour and pen-and-ink drawing by [[Francis Grose, 20 October 1775]]By the 18th century, the stone of the castle had blackened, its battlements had decayed, and the castle ditch was being used for rubbish disposal.

John Soane rebuilt the prison between 1789 and 1793. The interior walls of the keep were removed and cells for the male felons built. The debtors and women prisoners were accommodated in a new building adjoining the east side of the keep. This building incorporated but obscured the traditional entrance to the keep, the Bigod Tower. This cost £15,000.

Wilkins continued by slating the gutted interior as

In the 18th century, the castle mound was being used by the city's inhabitants as a soil quarry and rubbish dump. Norwich Justices of the Peace petitioned the House of Commons for the fee simple of the castle, the shirehall and surrounding grounds to be vested in them. This was granted by Act of Parliament on 12 July 1806, thereby ending more than 700 years of royal ownership, and vesting the Castle in the Magistrates of Norfolk as a county gaol. or 1828, costing £50,000. Prisoner accommodation was extended across the top of the castle mound by new wings radiating from a central gaoler's house. This governor's house was octagonal, containing apartments for the gaoler's family, a prison chapel and a committee room, and featuring views over the three wings and the yards. 240 cells were in these wings, with 36 cells in the castle keep. A mill house with a treadwheel was installed to the right of the entrance, pumping water for use in the castle.thumb|A mid-19th-century engraving of Norwich Castle from [[Charles Knight (publisher)|Charles Knight's Old England: A Pictorial Museum (1845).]]Prison labour involved weaving matting and making sacks, prison clothing and shoes. In 1862, 134 average daily prisoners were in the gaol, with a total of 862 within that year. 103 of these were debtors. Officers of the gaol numbered around 20, including a governor, surgeon, chaplain, schoolmaster, engineer, matron, turnkeys, taskmaster and porter. a transfer of all prisoners to this site occurred on 2 August 1887.

Kett and his brother William were accused of high treason as leaders of a peasant revolt now known as Kett's Rebellion. After capture in Norfolk the brothers were held at the Tower of London and indicted. A special commission of oyer and terminer found both guilty and they were brought back to Norfolk for execution; Robert in Norwich and William in Wymondham. On 7 December 1549 at the behest of Edward VI Robert was 'drawn' from the Guildhall to the Castle and taken up to the battlements on the west face to be hanged in chains from a gibbet. A figurative roundel by sculptor James Woodford that decorates the central bronze entrance door to Norwich City Hall depicts the hanging.

James Rush

James Blomfield (or Bloomfield) Rush was hanged at the Castle for the double murder of Norwich Recorder, Isaac Jermy and his son at Stanfield Hall near Wymondham on 28 November 1848. The crime, trial and execution excited national as well as local interest. Rush was held in the Castle gaol from early December. His trial took place at the Norwich Assizes and a guilty verdict was pronounced on 4 April 1849. The convicted felon was marched to the scaffold at noon on 21 April 1849 and despatched by hangman William Calcraft in front of thousands of spectators.

thumb|upright|Boardman's plan for Norwich Castle Museum

The castle was bought by the city of Norwich to be used as a museum. The conversion was undertaken by Edward Boardman. Soane's cell complex within the keep was swept away and flooring and balconies installed. Norman style arches were built to support the new glazed roof. Wilkins's central gaoler's house and walled prisoner exercise yards made way for gardens and the cell blocks were converted to viewing galleries.

At 12:25 pm on 20 February 2012, a group of four men entered the museum, forced open a display case, and attempted to steal a rhinoceros head, planning to sell its horns. They were tackled by two members of staff and stopped from stealing the head. The horns on the head were replaced with replicas before it was put back on display. Five days after the attempted rhino head theft, Admiral Lord Nelson artefacts valued at £36,800, including medals, a gold mourning ring worth £25,000, a box of medallions, and a saucer from his tea service, were stolen from the museum.

Royal Palace Reborn project

thumb|The Castle Keep undergoing restoration works in 2021

After five years of reconstruction Norwich Castle was reopened in August 2025. The £27m redevelopment project - titled "Royal Palace Reborn " - funded mainly by the National Lottery Heritage Fund (£13m) and Norfolk County Council was delayed by the Covid pandemic and discoveries during the rebuilding. Work started in 2020 with an expected completion in 2022. Later additions to the building were removed exposing the eastern wall of the keep and a new entrance. The rebuilding included accessibility provisions for visitors to see all five floors including full access to the battlements. A new lift allows wheelchair access and there is a tactile map to help blind and partially blind visitors.

thumb|left|upright|The recreated banquet hall with a throne in 2025

The interior of the keep was removed and floors reinstated in their original position with partitions to recreate the rooms including The Great Chamber, a banquet hall and medieval communal toilets. The interiors of the rooms are furnished and decorated. Medieval clothing is available for visitors to wear. Animations describing its original origins are projected on walls of the keep. The museum handbook says “The newly transformed spaces now enable visitors to see and explore the rooms of the royal palace, filled with the types of furniture, textiles and painted decoration that could have greeted Henry I when he stayed in Norwich in 1121”. A new Gallery of Medieval Life in partnership with the British Museum