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Earthwork Castles of Gwent and Ergyng AD 1050-1250: Mouse Castle

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1050 - 1250


This summary concerning Mouse Castle is an extract from a Doctoral thesis by Dr N Phillips, University of Sheffield (2005), entitled ‘Earthwork Castles of Gwent and Ergyng, AD 1050-1250’. This thesis is concerned with the earthwork and timber castles built in the southern March of Wales, addresses the presence of the castles and discusses their roles as weapons of conquest and structures of administrative control.


MOUSE CASTLE Grid: SO 24827 42458




This is an awkward castle to reach, travelling east from Hay on Wye along the B4348. After passing through Cusop a small road to the left is sign-posted Dorstone. At a distance of about 2km the road reaches the top of the pass and a small lane leads to the left. At the end of the lane is a private house, and a pathway to the summit.


The view from the end of the lane can be seen in the first photograph (Vol. 2. plate 172). The castle is covered by the trees to the left. At the edge of the trees, on the brow of the hill it is possible to see part of the outer eastern rampart. Mouse castle occupies the summit and the path follows a very extensive rampart and ditch system that is apparently Iron Age in date. The site itself is unfortunately covered in vegetation no where more so than the motte itself, shown in the first photograph (Vol. 2. plate 1732). The motte is the mound on the right and the dip in the middle is part of the motte ditch on the east. The motte itself is flat on top, with exceptionally steep sides. It was not possible to get a good view of the site on the ground, and so a plan of the site would give the best chance of explaining the layout (Vol. 2. figure 86). The plan shows how much of the site is still recognisable and how extensive its layout was. Unfortunately the graphic representation does not adequately illustrate the height of the ramparts. Also missing is the obvious modification done to the precipitous slope. The third photograph shows the area to the east of the motte, between the two ramparts (Vol. 2. plate 174). The area does still show evidence of possible building platforms. The last photograph shows the western edge of the rampart at the point marked entrance (Vol. 2. plate 175).

Topographic survey: (Survey 32)

The earthwork at Mouse Castle is located on the top of the summit of a hill overlooking the River Wye. The site consists of a motte 5.16m high with a surface area of 321.322m²; which may have been cut from the hill rather than raised above it, a large bailey and five sections of an encircling earthen rampart, one of which has an outer height of 4m. There are suggestions that the rampart formed a complete circuit of the hill but vegetation obscures most of the south-west of the site and erosion has also had a detrimental effect. The extent of the site, the identifiable area, measures some 7194.499m². It is unusual for such a high position but this may be representative of its importance. Conversely, the majority of the site may be Iron Age with the Normans just using part of it. A similar interpretation will be seen below at Twmbarlwm.

Strategic position:

The location of the site is extremely defensive and there is the possibility that it is an example of the re-use of an existing fortification, the earlier site being an Iron Age hill-fort. The site is an obvious choice for a lookout point and would have given a very good strategic position to the occupants of such a castle. Mouse Castle stands on high ground above the River Wye and from its vantage point, only the area to the south-east is higher.

The entire hill on which the site stands shows evidence of extensive scarping, which again would be more typical of an Iron Age site. The Norman influence seems to be the motte and an extensive bailey built within the outer ramparts. Atypical of the configuration is the position of the motte which would have been better placed towards the edge of the western bank in order to maximise the defensive capabilities of the steepest slope. It is possible that the unusual position for the motte could have been dictated by the existence of a pre-standing structure.

Documentary evidence

Primary reference:

Mouse Castle may exist in Db.H under the manor of Kingstone. ‘Before 1066 Cusop belonged to this manor and King Edward held it; Roger of Lacy holds it from the king (Thorn and Thorn 1983. 179c). Marshall suggested that the castle was built by Roger de Lacy as he held part of Cusop from the King (1938. 151).

However, the interpretation of Cusop as Mouse Castle is based on the typology of the site at Cusop dealt with earlier in this chapter. The form of the site at Cusop is of a much later fortified house rather than a motte and bailey castle.

Modern reference: HWCM1227

Additional references:

VCH 1908. 235.

RCHME 1931. 47.

King 1983. 204.

Interpretation: Motte and bailey (Early)

The interpretation of the site, based on actual remains, survey and location is that the site 259

probably functioned primarily as lookout point. The overall size, however, would suggest that a large garrison may have been employed here. The site would have been very effective as the most north-easterly point of Norman control prior to the move into Brycheiniog in 1090. Evidence from the survey, providing the shape and size of the motte, would tend to suggest that the site was of an early period as there are signs of inner defence between the motte and the bailey.



The material is copyright by the author, and is reproduced here from the Archaeology Data Service website of the University of York for research purposes under their terms of use


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