Castle Acre Castle, town defences and Bailey Gate


Heritage Category:
Scheduled Monument
List Entry Number:
Date first listed:
Date of most recent amendment:


Ordnance survey map of Castle Acre Castle, town defences and Bailey Gate
© Crown Copyright and database right 2019. All rights reserved. Ordnance Survey Licence number 100024900.
© British Crown and SeaZone Solutions Limited 2019. All rights reserved. Licence number 102006.006.
Use of this data is subject to Terms and Conditions.

The above map is for quick reference purposes only and may not be to scale. For a copy of the full scale map, please see the attached PDF - 1017909 .pdf

The PDF will be generated from our live systems and may take a few minutes to download depending on how busy our servers are. We apologise for this delay.

This copy shows the entry on 23-Jul-2019 at 06:16:12.


The building or site itself may lie within the boundary of more than one authority.

King's Lynn and West Norfolk (District Authority)
Castle Acre
National Grid Reference:
TF 81823 14922

Reasons for Designation

A shell keep castle is a masonry enclosure, extending around the top of an earlier motte or castle ringwork, and replacing the existing timber palisades; there are a few cases where the wall is built lower down the slope or even at the bottom. The enclosure is usually rounded or sub-rounded but other shapes are also known. A shell keep is relatively small, normally between 15 and 25m diameter, with few buildings, and perhaps one tower only, within its interior. Shell keeps were built over a period of about 150 years, from not long after the Norman Conquest until the mid-13th century; most were built in the 12th century. They provided strongly fortified residences for the king or leading families and occur in both urban and rural situations. Shell keep castles are widely dispersed throughout England with a marked concentration in the Welsh Marches. The distribution also extends into Wales and to a lesser extent into Scotland. They are rare nationally with only 71 recorded examples. Considerable diversity of form is exhibited with no two examples being exactly alike. Along with other castle types, they are major medieval monument types which, belonging to the highest levels of society, frequently acted as major administrative centres and formed the foci for developing settlement patterns. Castles generally provide an emotive and evocative link to the past and can provide a valuable education resource, both with respect to medieval warfare and defence, and to wider aspects of medieval society. All examples retaining significant remains of medieval date are considered to be nationally important.

The earthworks of Castle Acre Castle have been described as being among the finest surviving in England, and the complex sequence of development revealed in the excavations in the upper ward is in some respects, and so far as is known, unique. The size of the castle and the grand scale of the buildings within it reflect the power and wealth of the de Warenne earls who were, in the 11th and 12th centuries, among the leading magnates in the country under the king. The amount of archaeological evidence recovered during the limited excavations is indicative of what is likely to be preserved in the remainder of the castle, which will retain much additional information relating to the construction and development of the lower ward, its defences and the buildings within it, and to the later use of the castle. The infilled ditch around the southern end of the lower ward is likely, in addition, to contain waterlogged deposits in which organic materials, including evidence for the local environment during the medieval period, is likely to be preserved. The excavations have also demonstrated that evidence for earlier occupation of the site, predating the construction of the castle, is contained in the buried soils beneath the 11th and 12th century earthworks. The direct archaeological and historical association between the castle, the 12th century planned town and the priory (also founded by the de Warennes) which lies to the west, give the monument additional interest. As a monument in the care of the Secretary of State, maintained for public display, the castle is also a valuable educational and recreational amenity. The planned town is one of several established in Norfolk and, because it has been affected very little by later development, the principal elements of the original layout remain clearly apparent. The survival of much of the surrounding ditch and part of the bank as visible earthworks, and of the north gate of the town, are especially worthy of note.


The monument includes the earthworks and other structural remains of Castle Acre Castle, the remains of the defensive works which enclosed the area of the Norman town to the west of the castle, and the gatehouse which guarded the northern entry to the town. These features are located in the southern part of the modern village of Castle Acre, on the northern slope of the valley of the River Nar, above the point where the river is crossed by the Peddars Way.

The visible remains of the castle, which are Listed Grade I and are in the care of the Secretary of State, include a roughly circular upper ward, with an adjoining, sub-rectangular lower ward on the south east side and a roughly triangular barbican (defensive outwork) to the east. The upper ward is surrounded by a deep ditch, now partly infilled but still open to a depth of 3m-4m, and an inner bank surmounted by a curtain wall, and contains the standing ruins of a massive masonry building, with buried remains of associated, less substantial buildings. The outer ward is also surrounded by a ditch, with internal banks on the east and west sides, and fragmentary remains of a wall crowning the banks and closing the southern end. On the south side of the upper ward are the remains of a gatehouse which guarded the entry from the lower ward, and there are remains of two other gatehouses, sited at the junctions between the defences of the upper and lower wards on the east and west sides and giving access to the lower ward from the barbican and town respectively.

The walls of the main building in the upper ward, exposed and consolidated after part excavation between 1971 and 1977, display evidence of two major alterations, and limited investigation of the defences surrounding it have shown that these, also, were strengthened and enlarged twice. The original building, which is dated to the later 11th century and was probably constructed soon after the Conquest of 1066, was a strong hall, square in plan and of two storeys, divided by an internal east-west spine wall. The outer walls, approximately 2m thick at the base and constructed of mortared chalk rubble faced with flint, contain the remains of blocked, single light windows to the east and west and a blocked door opening at ground floor level in the south wall, as well as internal features such as a chimney flue in the north wall, and sockets for the joists to support the upper floor. Two small masonry buildings, no longer visible, abutted the outer face of the north wall. The house and associated structures stood within a courtyard surrounded by a ditch and an internal bank 3.3m high which survives as a buried feature beneath the later earthworks. The bank probably supported a timber palisade but was not strongly defensive. The gatehouse on the south side of the upper ward was inserted into the inner bank to replace an earlier timber structure, evidence for which was observed in excavation. It is rectangular in plan, with inner and outer openings, and the surviving walls are constructed of mortared chalk rubble. Part of the springing of the round-headed inner gate arch is preserved on the west side.

The major alterations to the house are dated to around 1140, during the `anarchy' of the reign of King Stephen and were designed to convert the building into a keep. The ground floor openings in the outer walls were blocked and the walls themselves were doubled in thickness by the addition of a masonry lining abutting their inner face. The straight junction between the two is still clearly visible. Two well shafts are incorporated within the thickness of the lining walls at the north east and south east angles. During this conversion, the ground floor level was made up to approximately its present height by the dumping of soil and chalk rubble to a depth of approximately 1m. Subsequently, in a second major alteration to the building, the walls of the southern half were demolished to ground level, and the spine wall was strengthened and refaced on the outer side to form the southern wall of the reduced keep, which still stands to a maximum height of about 8m.

The associated strengthening of the surrounding defences included, in the first stage, the enlargement of the ditch, the raising of the bank by approximately 2m, and the construction of a curtain wall of chalk rubble faced with flint. In the second stage, which probably followed the reduction in size of the keep, the bank on the north side of the ward was further raised to its present height of up to 9.5m above the original ground surface, and the height of the curtain wall on that side was also increased by building on to the existing masonry. Although the wall on the east side of the ward is very ruinous, and in places only the footings survive, parts on the north and north west side still stand to the height of the parapet walk, and the difference in height and construction between the original wall on the south side and the augmented wall to the north remains apparent. In addition to part of the parapet walk, the wall to the north displays the remains of other original features, including buttresses on the outer face and a diagonal vaulted passage through it, perhaps to an external tower or postern. The tail of the enlarged bank encroached on the interior of the ward, raising the ground surface on the north side to the height of the first floor of the keep and on the south side to a somewhat lower level. Excavation of this surface to the west and north west of the keep uncovered the flint rubble footings for timber framed buildings against the inner face of the curtain wall. Modifications of the gatehouse associated with the later fortification included the raising of the outer threshold and the partial blocking of the gate arches so as to narrow the entry.

The remains of the western and eastern gatehouses to the lower ward are also exposed, together with the footings of parts of the curtain walls linking them to the wall around the upper ward to the north. The ruined walls of the western gatehouse include the bases of twin drum towers on the outer, western face, and the remains of door openings on either side of the gate passage. The freestone sills and parts of the lower jambs of these doors survive, with some of the original ashlar facing at the base of the passage walls, including parts of the rebates for double doors in the inner and outer gate openings, and of grooves for a portcullis. Slots for draw bars are also visible in the rubble core of the northern wall above this level. The door on the south side of the gate passage opens into a partly excavated chamber beneath the adjoining bank of the lower ward, and the door on the north side into a small rectangular chamber outlined by wall footings. Adjoining the outer face of the north wall of this chamber is the base of a garderobe (latrine) shaft from a now vanished upper floor. The eastern gatehouse is less well preserved, but the remains are sufficient to show that it was a less elaborate structure. Excavations in the ditches opposite the eastern gatehouse and the gatehouse of the upper ward revealed evidence for timber bridges, now replaced by modern structures which are not included in the scheduling.

The barbican, which guarded the eastern gate to the lower ward, is protected by a substantial ditch and inner bank, and a gap in these earthworks on the eastern side marks what is thought to be the original entry. Adjoining the gap is a low, sub-rectangular earthwork which probably marks the site of the gate. A length of masonry across the ditch at the southern end is all that remains visible of the wall which would originally have stood on the earthworks and linked with the curtain walls of the upper and lower wards, but further evidence for this is likely to survive beneath the surface of the bank, which has not been investigated.

The earthworks of the lower ward are on a similar scale to those of the upper ward. The foundations of the curtain wall are visible in places on the surface of the banks, and part of it still stands to a height of up to 7m on the west side. Another length of wall, faced externally with coursed flint and including a rectangular opening, stands across the southern end of the enclosure. Here the bank is very slight, but immediately to the south of the wall is a steep scarp above the flood plain of the river. The ditch at the foot of the scarp has become completely infilled and is no longer visible, but limited excavations prior to the installation of a sewer in 1987 have confirmed that it survives as a buried feature and was at one time water- filled.

Within the lower ward, the outlines of three buildings are clearly defined by turf-covered wall footings. The largest, in the middle of the enclosure, is a rectangular great hall, aligned on an east-west axis, with a solar (private apartment) at the eastern end. A much smaller, square building to the west of this was probably a detached kitchen, and another rectangular building to the north was perhaps a chapel. The hall was almost certainly built to replace the house in the upper ward, after the conversion of the latter to a keep. Evidence for other, less substantial structures, including service buildings and stables, is likely to survive beneath the ground surface.

At the time of the Domesday survey in 1086, Castle Acre was held by William de Warenne, first Earl of Surrey (died 1088), who is thought to have been responsible for the building of the original, lightly defended house (domus defensabilis). The conversion of the house to a strong castle took place either during the time of his son (died 1138) or, more probably, his grandson (died 1148). Throughout the 12th and 13th centuries the castle continued to be an important administrative centre, and visits by King Henry III and his son Edward I are recorded, but during the 14th century it was neglected, and an inquisition on the estate of Richard Earl of Arundel, executed for treason in 1397, recorded the value of the castle as nil, indicating that by then it was derelict. The estate, including the castle, was eventually acquired by Sir Edward Coke in 1615.

The Norman planned town occupied a rectangular area some 4.25ha in extent (approximately 225m north-south by 188m east-west) immediately to the west of the castle. It was enclosed by a ditch and an internal bank surmounted by a wall, with gates on the north and south sides, and the remains of these defences are included in the scheduling. The bank and ditch on the west side and along much of the south side survive as substantial earthworks, known as Dyke Hills. The ditch is approximately 17m wide and remains open to a depth of approximately 3m, and the bank stands to a height of up to 3m. On the south side, where the ground slopes steeply down to the river, the bank decreases in height and disappears towards the eastern end, and the ditch immediately to the west of Bailey Street appears as a steep, south-facing scarp above a slight depression in the ground surface. Immediately to the east of Bailey Street, the ditch has been largely infilled, although the inner edge remains visible as a slight scarp and the rest will survive as a buried feature. The eastern end originally abutted the castle ditch at the southern end of the outer ward, but this section has been removed by a later quarry. The earthworks along the northern side have been levelled, but evidence recorded during installation of sewers has confirmed that the ditch survives as a buried feature beneath Stocks Green and the High Street and, at the eastern end, the inner edge of the ditch and traces of the outer edge can still be traced, curving southwards to meet the ditch around the inner ward of the castle. Little remains standing of the town wall except the eastern end on the south side, blocking the castle ditch, but other remains, including foundations, are likely to be preserved below the surface of the bank around the western side.

Broken stubs of the wall can also be seen on the eastern side of the partly ruined northern gate, known as the Bailey Gate, which stands at the northern end of Bailey Street. This is massively built of mortared flint with stone dressings and, although now roofless, still stands to full height, with twin drum towers fronting recessed inner and outer arches. On the inner faces of the walls are remains of the slots for a portcullis. The lower end of Bailey Street is a well-developed hollow way. Where it crosses the line of the wall, it is possible that evidence for the southern gate survives below the ground surface.

The houses and associated garages and outbuildings which stand above the buried section of the town ditch are excluded from the scheduling, together with all modern fences and gates, garden walling and paving, garden furniture, English Heritage signs and information boards, modern wooden bridges across the castle ditches, the surfaces of modern roads, driveways, paths and the visitor car park adjacent to the castle earthworks, street furniture, a transformer on the south side of the southern arm of the town ditch, service poles, and inspection chambers, although the ground beneath all these features is included.

MAP EXTRACT The site of the monument is shown on the attached map extract.


The contents of this record have been generated from a legacy data system.

Legacy System number:
Legacy System:


Books and journals
Coad, JG, Castle Acre Castle, (1984), 25
Coad, JG, Castle Acre Castle, (1984)
Coad, J G, Streeten, A D F, Warmington, R, 'Archaeol J' in Excavations at Castle Acre Castle, Norfolk, 1975-82, , Vol. 144, (1987), 256-307
Coad, J G, Streeten, A D F, 'Archaeol J' in Excavations at Castle Acre Castle, Norfolk, 1972-77, (1982), 138-301
Coad, J G, Streeten, A D F, 'Archaeol J' in Excavations at Castle Acre Castle, Norfolk, 1972-77, (1982), 138-301
Leah, M, 'Norfolk Archaeology' in Excavations and Watching Brief at Castle Acre 1985-86, (1993), 494-507
Leah, M, 'Norfolk Archaeology' in Excavations and Watching Brief at Castle Acre 1985-86, (1993), 494-507
Garry, M A, (1996)


This monument is scheduled under the Ancient Monuments and Archaeological Areas Act 1979 as amended as it appears to the Secretary of State to be of national importance. This entry is a copy, the original is held by the Department for Digital, Culture, Media and Sport.

End of official listing

Your Contributions

Do you know more about this entry?

The following information has been contributed by users volunteering for our Enriching The List project. For small corrections to the List Entry please see our Minor Amendments procedure.

The information and images below are the opinion of the contributor, are not part of the official entry and do not represent the official position of Historic England. We have not checked that the contributions below are factually accurate. Please see our terms and conditions. If you wish to report an issue with a contribution or have a question please email [email protected].