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Monmouth Castle

Also known as, or recorded in historical documents as;
Mingui; Mori; Monemude

In the community of Monmouth.
In the historic county of Monmouthshire.
Modern authority of Monmouthshire.
Preserved county of Gwent.

OS Map Grid Reference: SO50691289
Latitude 51.81233° Longitude -2.71704°

Monmouth Castle has been described as a certain Timber Castle, and also as a certain Masonry Castle.

There are masonry ruins/remnants remains.

This site is a scheduled monument protected by law.
This is a Grade 1 listed building protected by law*.


Monmouth Castle was established between 1067-71. Partially demolished in 1647, from 1672 it formed the setting of Great Castle House (NPRN 36568). It became associated with the militia during the nineteenth century. The surviving remains include a roughly oval enclosure, approximately 90m east to west by 140m, defined by scarps within which, besides Great Castle House, there survive only the ruins of an eleventh to twelfth century great tower and a thirteenth century hall, both much altered in the later medieval period. (Coflein)

Castle established by William fitz Osbern in the late C11. The remains of the great tower date to the first half of C12. Later remodelled by the Lancasters. Birthplace of Henry V. (CADW)

Only a fragment is left of this once important castle; the curtain wall, gatehouse and great round keep, which stood until the Civil War where the Great House now stands, have all completely vanished. All that is left is the ruined Great Tower and Hall. These stand on the edge of a precipitous slope down to the river Monnow, on the west side of what was the castle ward. This was roughly circular, surrounded on the west and north by the river and on the east and south by a wall and ditch, which is still partly apparent in back the gardens behind Agincourt Square. Half-way along Castle Hill Road was the entrance, consisting of a bridge and strong gatehouse. William fitz Osbern chose this strategic position, guarding crossings of the Wye and Monnow rivers, for one of his marcher castles sometime between 1067 and 1071, when he died. The Great Tower is similar in style to that at Chepstow, and was certainly built by about 1150. What can be seen are parts of its east and south sides. The west side fell in 1647, the north-west side remains but can not be seen from the town side, and a house lies over the rest. This was a fine early Norman rectangular two-storeyed building with the hall and main apartments on the main floor and a cellar or undercroft below. The east wall displays some Norman features: the small round-headed windows, the fragment of simple string course and the flat pilaster buttress in the south-east corner, one of a series which originally continued all along the wall. The entrance was at first-floor level on the south side. The castle was held uneventfully by Norman lords as the headquarters of an independent lordship until 1267, when it was granted with the Three Castles (White, Grosmont, and Skenfrith) to Henry III's son, Edmund Crouchback, when he became earl of Lancaster. He immediately built the large rectangular building to the south of the Great Tower, known as the hall. It was a single storey building containing one large room used for the holding of courts. It continued in use as such right up to the 17th century. All the walls, except the north, stand almost to their full height. The entrance was the gap in the wall in the north-east corner, on the west side of which a moulded base of a door jamb is visible. The fireplace was in the middle of the north wall, and there were windows, now blocked, in the south wall. A later medieval window, also blocked, was inserted in the east wall. In the mid-14th century, during the lordship of Henry of Grosmont, 1st duke of Lancaster, the upper part of the Great Tower was transformed by the insertion of large decorated windows. The elaborate frame of one of these is visible in the east wall. The original entrance was replaced by a tall door, and the tower was reroofed. At this stage, 12th-century corbels of carved heads were reset high up in the east hall, where they are still visible. This tower was almost certainly the birthplace of the future King Henry V in 1387. The end came for the castle in the Civil War, when it changed hands three times and was eventually slighted by the Parliamentarians. A local man's diary for 1647 records that on 30 March the townsmen and soldiers began pulling down the great round tower, which stood where Great Castle House now stands, and that on 22 December 'about 12 o'clock, the Tower in the castle of Monmouth fell down, upon its side, whilst we were at sermon'. The Great Castle House, built in 1673 by Henry Somerset, later the duke of Beaufort, was to replace Raglan as his family's residence in the country following the Civil War. In 1875 the house became the headquarters of the Royal Monmouthshire Royal Engineers (Militia), and as such it remains one of the few British castles still in military occupation. (Taylor, 1951)

The Castle is situated on a commanding site on the east bank of the river Monnow at the highest point of the town and just north of the town square.
Substantial portions remain of the C11-12 Norman castle. This was developed during the C13-14 to form the nucleus of an elaborate defensive system in the centre of Monmouth, together with the town walls and ditches and other surviving features such as the Dixton Gate (now incorporated in The Nag's Head Inn (qv), Monnow Bridge (qv) and Clawdd du Bridge (qv). The Castle was extended and improved by John of Gaunt in the mid C14 and was the birthplace in 1387 of Harry of Monmouth, later Henry V. The Castle was involved in the Civil War on the Royalist side after which it rapidly became ruinous. The great Round Tower, illustrated by Speed, was demolished in 1647 to make way for Great Castle House (qv), which was constructed in 1673 using the recovered stone. The Great Hall continued in use as a courtroom until 1724 which probably ensured the survival of at least part of the structure. Today significant remains exist only of the Keep or Great Tower which was much altered in C14, probably c1360 and of the Great Hall which was added in mid C13, possibly 1270. The Castle was in the ownership of the Worcester and Beaufort families until the C20 when it became vested in the Ministry of Works.
Built largely of purple and red local sandstone rubble with quoins and repairs in dressed sandstone, and patching, much of this is C20, to the projecting corners of the Great Tower. The surviving walling is more considerable than at first appears. The Great Tower is a large rectangular one with wide faces and three clasping buttressed corners. The walling between is largely missing on the north (river) side and at the south-east corner; slighted following the Civil War and then robbed afterwards to build Great Castle House in 1673. The architectural character of the openings changes in the upper walling as does the stone type indicating a major strengthening and general improvement in the late C14. One opening at this level has a cusped ogee head while the doorway into the Great Hall has a head with a triple mould. The adjoining Great Hall is more ruinous despite having stayed in use as a courtroom until 1724. The north and west walls survive, the taller having two large windows. (Listed Building Report)
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This record last updated 28/06/2017 18:13:03