id: sig-20260722-report-mm003 site_id: gb-chepstow-chepstow attribute: designation_report value: 'Reference Number MM003 Name Chepstow Castle Date of Designation Status Designated Unitary Authority Monmouthshire Community Chepstow Easting 353352 Northing 194109 Broad Class Defence Site Type Castle Period Medieval The following provides a description of the Scheduled Ancient Monument. This monument comprises the remains of a medieval castle begun in 1067 by William fitz Osbern, earl of Hereford. It is situated on a limestone promontory on top of tall cliffs overlooking the river Wye. The castle dominated the medieval town that developed around its foot; the bridge which provided access for travellers into south Wales; and the river which was a main highway of the period. The oldest building in the castle is the Great Tower. Rectangular and measuring 36m long by 14m wide, it dominates the centre of the castle. The tower contains some reused building materials, probably brought from the ruins of the Roman town Venta Silurum – modern day Caerwent. It was probably used as an audience chamber – a place where the King conducted ceremonial or judicial functions. Connecting the Upper and Middle Baileys is the gallery, a single-storey building which formed a roofed passage. The Upper Bailey is likely to have been the centre of William fitz Osbern’s original Norman castle. The end of the Upper Bailey is closed by Marshal’s Tower – a two storey rectangular tower built by William Marshal (d. 1219) in the very early thirteenth century. The first floor contains the remains of an elegant chamber lit by five finely dressed windows. Beyond the Upper Bailey gateway is a small defended platform which crosses a deep, rock-cut ditch to the Upper Barbican. This ditch marks the western limit of the castle under the Normans and William Marshal. The heavily defended Upper Barbican was created in the second quarter of the thirteenth century when the defensive line was extended further along the promontory to the west. The curtain wall runs from Marshal’s Tower in the Upper Bailey across the ditch to the south-west tower. From the south-west tower the curtain wall curves around to the Upper Gatehouse. From this gatehouse access there was access to the castle’s gardens and the home farm. The curtain wall continues to cut off the end of the promontory and returns for a short length to deter any attackers from clambering around the cliff into the castle. The walls and towers of the Middle Bailey were added to the castle by William Marshal in the late twelfth century as part of his complete remodelling of the castle’s defences. However, the break in slope near the centre of this bailey may mark the position of the western defences of the Norman castle. The entrance to the Middle Bailey is through a simple gateway in the curtain wall which is protected by a three-storey D-shaped tower projecting forward from the curtain wall. A low curtain wall links this tower to another of very similar design at the outer angle of the middle bailey, but this was significantly modified with the insertion of fireplaces and doorways during the early sixteenth century. The curtain wall returns from the corner tower to a D-shaped tower – modified during the Civil War. The Middle Bailey does not seem to have contained any buildings in the Middle Ages, perhaps because they would have reduced the grandeur of the approach to the main entrance of the great tower. The Lower Bailey is the most complicated part of the castle with buildings of many different periods represented. The bailey was added to the castle by William Marshal in the late twelfth century and substantially remodelled by Roger Bigod a hundred years later with the construction of a large domestic range and Marten’s Tower. Bigod developed a suite of apartments and lodgings appropriate for one of the richest magnates of King Edward I’s reign. The domestic range consisted of two adjoining blocks linked by a central service passage, built to take advantage of the changes in height across the site. The hall and ceremonial and private chambers of the earl occupied the higher ground to the west, and the service rooms, kitchen and additional accommodation were constructed below. The earl’s chamber (known as the ‘gloriette’) was situated above the service rooms. This room would have been a combination of bedchamber, a private sitting room and an audience chamber. To earn the name gloriette, this chamber must have been very special or exotic. Close to the entrance of the castle, Marten’s Tower, or the ‘New Tower’ as it was referred to in Roger Bigod’s accounts, was started around 1288 and brought into use by 1293. It was begun after the earl’s domestic apartments had been completed and almost certainly replaced an earlier tower dating from the Marshal period. Marten’s Tower has been described as a ‘mural tower to end all mural towers’, but it is far more than a simple defensive work. In addition to the three storeys visible from the courtyard, there is a basement, a room in the roof space and a private chapel carried out over the curtain wall to the east. The castle well is just alongside the door. The Main Gatehouse is of revolutionary design. It consists of two round towers of slightly different diameter built close together and well equipped with arrowloops to provide a wide field of fire. Outside there was a small barbican which further protected the entrance. The round tower to the left was the castle’s prison and that to the right was a guardroom. This is thought to be the oldest twin-towered gatehouse in Britain and demonstrates that William Marshal and his master craftsmen were at the forefront of castle design, building on their experiences in France and the Holy Land. A number of wooden doors have survived at Chepstow Castle and these have been dated using dendrochronology (tree-ring dating). The doors in the upper and middle bailey gateways at Chepstow are made of two layers of elm and oak boards, clenched together with a regular pattern of iron nails. At over 800 years old, they are believed to be the oldest castle doors surviving in Europe. This monument is of national importance for its potential to enhance our knowledge of medieval social and domestic life and warfare. The scheduled area comprises the remains described and an area around them within which related evidence may be expected to survive.' source_url: http://cadwpublic-api.azurewebsites.net/reports/sam/FullReport?lang=en&id=3137 source_title: Scheduled Monument Full Report — Chepstow Castle publisher: Cadw observed_date: '2026-07-22' collected_by: scripts/build_assessment_batch.py confidence: high notes: The designation text. Assess the six bands against THIS evidence only; omit any band it does not speak to.