Full Report for Listed Buildings

Summary Description of a Listed Buildings

Reference Number
Building Number
Date of Designation
Date of Amendment
Name of Property
Great Castle House  


Unitary Authority
Street Side
Great Castle House is situated in the castle enclosure at the highest point of the town and just north of the town square.  


Broad Class

Built by the first Duke of Beaufort in 1673 (dated), Henry Somerset as he then was, and at that time President of the Council of Wales and the Marches. On the site of the Great Round Tower of Monmouth Castle and likely to have been built from the recovered stone from that and from the Castle Gatehouse also demolished at that time. The old fashioned nature of the design indicates a local architect, and no attribution has so far been made. The house was built as the town house for the Beauforts on their Monmouthshire estates, which had largely been the property of Tintern Abbey and were taken over by Lord Somerset after the Dissolution in 1539; and for ceremonial purposes concerned with the Duke's Presidency. The house was, however, quickly relegated in importance as Troy House came into use in 1684. It was now used for offices and for the agent of the Beaufort estates, but in c1700 it was taken over for state use as the Assize Courts which moved from the Great Hall of the Castle (qv). This use involved the complete rearrangement of the first floor as the Court Room. This lasted only until 1724 when the Courts moved into the new Shire Hall in Agincourt Square (qv), but the house continued as the Judge's Lodging. Later it reverted to the Beaufort Estate and was then tenanted for various uses including a girls' boarding school, which it was when Archdeacon Coxe visited in 1798; Castle House 'now occupied by Mrs. Elizabeth Tudor, mistress of the most respectable school for young ladies in this part of England'. In 1852 Great Castle House became the headquarters of the Monmouthshire Militia and side wings were added in 1863 after a lease was granted on the buildings by the Duke of Beaufort. The house was passed into state ownership when the Beauforts sold up their Monmouth estates in 1901 and retired to Badminton House. The house is now occupied as the regimental headquarters of The Royal Monmouthshire Royal Engineers (Militia), the senior non-regular unit of the Army and the left wing also houses the Regimental Museum (opened 1989).  

Old red sandstone ashlar with much patching,probably rendered and limewashed formerly; old tile roof with stone and brick chimneys. The style of building, however, tends to reflect the spirit of an earlier age. It is a fine symmetrical design but more Jacobean than Carolean in character with only the slightest influence of classicism. Three storeys, attic and cellar, formerly free standing, the wings were added in c1863. Five bay front, 1 + 3 + 1, the outer bays wider, and projecting slightly as wings, so originally a semi-H-shaped plan harking back to c1600, which should be compared with the contemporary, but much more sophisticated, Tredegar House (qv). Plinth at ground floor. Heavy moulded string courses above windows which are of 3-lights in the outer bays and 2-lights in the centre, with transoms on the ground and first floors. A central feature rising through the ground and first floors framing entrance door, and first floor windows, consisting of pairs of slightly projecting columns, partially fluted on the first floor, supporting central spoked lunette, which reads '1673'. Ribbed double doors with C19 lamp at centre. Steps up to door. The first floor central window appears to have been altered, but its original form is uncertain. The second floor is lower with smaller windows. All windows with lattice glazed casements except for the basement windows of which only the fixed top parts are above ground. Heavy coved eaves cornice. Hipped roof with three hipped dormers with casements, tall brick stacks at each end. At either side are different but closely matching early C20 wings of two storeys on left, and one storey and basement on right with coved eaves cornice, tile roofs and mullioned and transomed windows. The left wing has five bays with the first set forward, two arched doorways with voussoired surrounds, strong string course between floors, two brick stacks. The right wing is in five straight bays with a door on the upper floor in bay 4, no string course, brick stack. The return elevation has a 3-light window below and a 2 and a 3-light mullion-and-transom window above. The rear elevation is more altered with partly glazed additions, but the projecting stair wing can be seen.  

The interior has a large central hall with rooms on either side and the staircase in a tower behind. The Hall has a compartmented ceiling with two cast iron Doric columns added as support in the early C19. Early C18 panelling and joinery dating from the alterations of c1700 when the Assize Courts were brought in. The elaborate chimneypiece with its plaster overmantel and swags is of 1673. The room on the right (CO's office) has elaborate moulded panelling which appears C17 in character but does not fit against the cornice properly. The plasterwork, with the fine ceiling, is of 1673. The room on the left (Adjutant's Office) is very plain in comparison. The main dog-leg staircase has widely spaced twisted balusters, a closed string, panelled newel posts with ball finials and moulded handrail. All these features are repeated on the wall side. The stair rises to the attic, but with plainer balusters on the top flight. The secondary staircase, which is accessed through a studded iron door and rises to the first floor only, is narrower, but has a similar character and details. The first floor is now given over to one large room, once used as the Assize Court, although clearly formerly divided into five rooms; the Criminal and Civil courts met together in the same room. There was originally a large room in the centre and smaller rooms front and rear in either wing. The present room has five distinct plaster ceilings of differing character, some heavily and exuberantly moulded with wreaths, fruit, figures, circles and ovals, with daring undercuts and projection. All these are of 1673, but the panelling and fireplaces are c1700 and this can be clearly seen where the panelling does not fit properly against the cornices. Two fireplaces with bolection mould surrounds, one in speckled grey marble. This remarkable room is now the Regimental Officers' Mess. Plain office conversions on the upper floor. The attic shows a roof construction which has had considerable alterations and timber replacement as well as a large C20 timber reinforcement. The principals and many rafters are C17 however. Extensive vaulted basement. The interiors of the added wings are both altered and utilitarian but continue with some of their original uses, especially the Quartermaster's Stores in the right wing. The left wing houses the Museum of the Royal Monmouthshire Royal Engineers on the ground floor and offices above.  

Reason for designation
Included and highly graded as an exceptionally fine example of provincial Carolean architecture and (along with The Shire Hall) is one of the two finest secular buildings in Monmouth.  

Cadw : Full Report for Listed Buildings [ Records 1 of 1 ]