The enclosure castle at Sherborne survives well as a combination of upstanding ruined structures and buried deposits, as recorded in part excavations on the site. The site is one of only two enclosure castles in Dorset and represents one of the best examples of 12th century architecture in the county. Sherborne Castle has a different internal design from many contemporary enclosure castles: a great tower formed part of a central block which, unusually, was arranged around a central courtyard. This design is comparable to that of a cloister, a factor which may reflect the ecclesiastical background of Roger de Caen who designed the structure at Sherborne as his own residence. The historical role of the castle is well documented and it is known to have formed the administrative centre of a large and wealthy estate. An extensive archive of records has been maintained.
The monument includes an enclosure castle with a central building, incorporating a great tower within a large bailey, an earlier Christian cemetery, and Civil War siegeworks at Sherborne, situated on a natural knoll in the Yeo Valley. The earliest deposits identified at the site include the remains of the Christian cemetery which dates from the ninth century AD. Part excavations have located burials across the hilltop, although many had been disturbed by the structures of the later castle. Some of the graves were found to have distinctive rounded ends. The ditches of a rectangular enclosure have also been identified nearby and this may be later than the cemetery. The function of the enclosure is uncertain. During the early 12th century an enclosure castle was built on the hilltop. The site is now known as 'Sherborne Old Castle', distiguishing it from the later residence now known as 'Sherborne Castle', 300m to the south. The enclosure castle had at its centre a block of buildings constructed of local stone, using a rubble core with Ham Hill ashlar facing. This was surrounded by a curtain wall and outer ditch, enclosing an octagonal area of 1.4ha. The natural hilltop was extensively levelled for the construction of the castle and to increase the gradient of the outer slopes, thus enhancing its defences. The central building survives as a partly upstanding ruin within the centre of the bailey. The great tower consists of a main block, and a turret on the west side and a southern extension. The central building dates from around 1130, although the surviving remains also include at least three additional phases of construction. The ground floor of the tower is divided by a spine wall, aligned north-south, supporting two barrel vaults linking with added groined vaults supported on a re-used 12th century cylindrical column. This vaulting is a later insertion. The west wall of the main block of the tower stands to first floor level and was supported by two buttresses. Access to the first floor was by means of an internal staircase situated on the northern side. The upper part of the south buttress of the tower retains its ashlar facing, and its eastern wall retains junctions with the demolished walls of the east range of the central building. The turret on the west appears to have possessed no means of direct access to the ground floor. A stone stair dating to the late 14th century, on the northern side of the turret also provided access into the tower. To the north of the great tower was a 12th century range of two storeys, which formed the northern side of a small courtyard. The northern range contained chapels on each floor. The ground floor was of four bays with buttresses to the north wall. The three bays to the east were vaulted with groined rubble vaults, and the western bay a barrel vault; all of which have collapsed. Much of the southern and eastern walls survive to their original height, as does the eastern part of the northern wall, however the remainder is now much ruined. The eastern wall has a window, the southern wall evidence of two entrances, and the northern wall several windows and a doorway. The former eastern range, linking the chapel range with the south range is now much ruined. Part excavations conducted at the site by Mr C Bean between 1932 and 1954 and Mr P White between 1968 and 1978 have identified additional structural foundations and buried deposits. The area south east of the central building was found to contain building foundations which have been interpreted as a kitchen block. The well to the south of this block was circular in plan, 1.5m in internal diameter and retained by walls constructed of Ham Hill Stone extending to a depth of 8.4m. Below this, the natural rock had been quarried out. The well was excavated to a depth of 12.8m; the modern water table was encountered at a depth of about 12m, and the well found to be rectangular in plan at its lowest level. At a depth of 3.5m there was considerable wearing of the wall surfaces. This has been interpreted as bucket-rub and may indicate the normal water-level within the well during its use. The well contained extensive archaeological deposits, including pottery, shells, domestic rubbish and the remains of timber lifting gear. The deposits dated from the 13th century and extended around the area surrounding the well-head. The foundations of substantial buildings were also located within the area adjacent to the south east corner of the curtain wall. These extended south from the tower for a distance of at least 53m and included traces of doorways thought to date from the 12th century. The foundations of a possible garderobe tower have been identified within the north western corner of the central building. The remains of a tiled floor were identified within the north eastern area of the Great Hall in the South Range. This included tiles arranged in alternating colours of yellow and brownish-green, and an outer border of tiles of similar alternating colours. The circuit of the outer walls was constructed as straight flanks enclosing an interior area, with dimensions of 143m by 100m, forming an octagonal plan. The curtain walls have been largely reduced to ground level along the northern and western flanks, although the eastern end of the northern flank and part of the north eastern flank stand to a height of 8.4m. The walls had an inner walkway and originally incorporated four towers. Two of the towers had gates providing access into the bailey. The main entrance was through the south west tower which faced towards the town and was designed to be impressive upon approach. This tower was built over the scarp of the ditch and had the appearance of a three storey structure from outside the castle, but only two storeys from within. The second entrance was provided through the smaller north eastern tower. On the northern flank there was also a central gateway protected by a small outer court from which a narrow barrel vaulted passage descended to the level of the former lake or mere on the northern side of the castle. Outside the bailey was a substantial rock-cut ditch which survives between 5m (in the south eastern corner) and 15m (in the south western corner) wide. On the southern side, the ditch has a depth of between 8m-10m below the base of the curtain wall. To the west of the site is a semi-hexagonal earthwork which is approximately 25m in diameter and c.1.5m high. This represents the remains of a Civil War siegework. To the north east the foundations of a small rectangular late 17th century building and the remains of 12th century ranges partly robbed out during the Civil War were excavated by C Bean. They are all within the area of the scheduling. Sherborne Old Castle was constructed by Roger de Caen, Bishop of Sarum 1107- 1139. Roger was also the Abbot of Sherborne and a principal advisor to King Henry I, who eventually assumed the role of vice-regent while Henry was abroad. Roger relinquished his abbacy in 1122, although he retained the episcopal estate surrounding Sherborne and Sherborne Castle. Following Henry's death in 1135, Roger lost royal favour and in 1139 the castle was seized by King Stephen. Later it was maintained as a royal castle and accommodation at the site was enhanced by the construction of a court with ranges on the west side of the central building. In 1354 the castle was regained by Bishop Wyvill of Salisbury and reused for administrative and residential purposes by the bishopric. As a result, less finance was available for the maintainance of the castle and this led to some contraction in the size and number of the internal buildings in use. Structures such as the garderobe turrets, areas of the west court and the northern postern appear to have been demolished during the 15th century. It may not have been until the late 15th century that any refurbishment or significant improvements were made to the site. Leland records that Bishop Langton built a new work at the western end of the hall during the period 1485-87, and part excavations suggest that an extension was added to the southern tower. During the 16th century extensive diocesan boundary changes contributed to a change in the ownership of the site. In 1592 Sir Walter Raleigh gained possession of Sherborne Castle and began to remodel the castle including the great tower and south west gate tower. However, he turned his attention to developing the former hunting lodge to the south of the castle as his home, and the castle became less important. During the Civil War, the castle proved useful as a Royalist stronghold and resisted a siege by Parliamentarian forces in 1642. However, following a further siege in 1645, the castle was stormed by the Parliamentarians on August 15th and surrendered to General Fairfax. The fortifications of the castle were slighted soon afterwards to prevent re-possession. This included the reduction of the eastern defences. From this time the castle remained unoccupied and, in the 18th century, its ruins were incorporated as a feature in the landscaped park and gardens of the former lodge to the south now called Sherborne Castle. Sherborne Old Castle is now in the care of the Secretary of State and is open to the public. It is also a Listed Building Grade I. (Scheduling Report)
Sherborne Old Castle 11.7.51 GV I Episcopal castle with curtain-wall and gatetowers. Built by Roger, bishop of Salisbury 1107-1135. Restoration begun by Sir Walter Raleigh in 1592, and soon abandoned. Castle partly demolished and rendered untenable, 1645. Rubble-stone walls, with close-jointed ashlar facing and freestone dressings. Curtain wall and gatetowers. Curtain-wall enclosed an area 470 ft by 330 ft with diagonal walls across the angles, forming an elongated octagon. Walling stands either side of the SW gatetower,in places on the north, south and east walls. SW gatehouse, C12, 4 storeys with a battered plinth and clasping buttresses. NW angle stands to full height, S side is more ruined. W face, facing of the outer archway has gone and only the segmental rear-arch remains. C16 restorations and alterations under Raleigh. (See RCHM). Present approach to gate, C20. Abutments and central pier revealed by excavations. NW Tower, foundations only. North gate and barbican, revealed by excavation, C12 and C13. Flanking the C13 buildings are the remains of wing-works with circular turrets at the outer angles. NE gate, foundations and some walling. SE tower, site only. Keep and attached courtyard of buildings at the centre of the bailey. Keep. C12, of at least 3 stages. Ground floor has a dividing wall running N and S., and supporting two barrel-vaults. These barrels run on into groined vaults, supported by a cylindrical column with a scalloped capital. South wall of the extension has externally a central buttress of segmental form. SW angle of the keep adjoins the S wall of the forebuilding, which stands to the top of the third stage. The forebuilding has clasping buttresses at the west angles. Late C16 stone staircase and terrace against north wall of forebuilding. 3 ranges of buildings, and an excavated S range stand round a central courtyard, originally with cloister-walks. W Ranges running N from Keep, W wall has pilaster buttresses and a moulded string-course. E wall of this range largely destroyed. Rubble (tufa) barrel vault. N range, 2 storeys, 4 bays, with clasping and pilaster buttresses externally. Ground-floors groined rubble vault over 3 E bays and barrel-vault over W bay. N wall has remains of former windows and openings upper floor round-headed windows decorated with chevron, and label with billet. Internal wall-arcading of intersecting arches, of which traces remain. Floor may have housed the chapel. East range, much ruined. East hall has pilaster buttresses and an original window in each of the 3 bays. Ground floor has a rubble barrel-vault of which the springing remains. S range, foundations found of N and S walls, probably housed the great Hall. The castle was held for the Crown in 1642 and 1645. (Listed Building Report)
Sherborne Old Castle was built as a fortified bishop's palace and castle during the early C12 on top of a natural knoll in the Yeo Valley. Its centre block of buildings were constructed of local stone, using a rubble core with Ham Hill ashlar facing. This was surrounded by a curtain wall and outer ditch. The central building survives as a partly upstanding ruin within the centre of the bailey. It dates from around 1130 AD, although the surviving remains also include at least three additional phases of construction. To the north of the great tower are the ruined remains of a C12 range of two storeys, which formed the northern side of a small courtyard. This range contained chapels on each floor. Part excavation between 1932 and 1954 and between 1968 and 1978 have identified structural foundations and buried deposits. The area south east of the central building contains the foundations of the kitchen block whilst the foundations of a garderobe tower have been identified within the north west corner of the central building. The remains of a tiled floor were identified within the north eastern area of the Great Hall in the south range. The curtain walls have been largely reduced to ground level along the northern and western flanks, although the eastern end of the northern flank and part of the north eastern flank stand to a height of 8.4 metres. To the west of the site is a semi-hexagonal earthwork which is 25 metres in diameter and circa 1.5 metres in height. This represents the remains of a Civil War siegework. Sherborne Old Castle was constructed by Roger de Caen, Bishop of Sarum 1107-1139 and was altered and refurbished between 1185-87 and in 1592. The castle became a powerful Royalist base during the Civil War and in 1645 fell after a fierce 11 day siege. Much of the castle was subsequently demolished and left in ruin. (PastScape)