Summary

The scheduled monument includes the keep of the tower keep castle at Canterbury, part of its bailey, a sample of land just outside the bailey, the postern gate of the later enclosure castle and the castle and city ditch which originated in the Romano-British period.

Source: Historic England

Details

The castle lies in what was the south part of the city; the southern bailey wall, built on the line of the earlier Roman town wall, became part of the medieval city wall. The city wall is separately scheduled (NHLE 1003554).

The keep, which measures 26m by 30m externally, has walls which are 2.7m thick. It comprises a thick (4m) rubble flint plinth at its base with bands of flint and Caen stone blocks above. There is no evidence that the plinth was faced in Caen stone blocks, but they may have been robbed out. The keep stands now to about 20m high and its square form denotes its Norman origin. It has buttresses clasping the angles and on the sides: one on each of the shorter sides and two on each of the longer sides. The keep originally had four round arched windows on each side, although because of its ruinous state not all survive. The interior has two cross walls and the remains of spiral staircases in the E and SW walls. Fireplaces composed of rubble set in herringbone pattern survive, set into the walls. There were at least three floors, marked by substantial beam-holes, though only beam-holes for the first floor survive. The upper floor has largely gone.

The keep, which is of typical Norman construction, originally had a first floor entrance via a forebuilding. The 1971 excavations on the west side of the keep by Miss L Millard with the Canterbury Archaeological Society located the foundations of this original entrance with its forebuilding. On the SE side of the keep excavation by Dr G Webster in 1939 showed that there was a later modification in the form of a probable C13 to C14 entrance with two round towers leading to a ground floor entrance.

The keep lies towards the SW side of the inner bailey. The only surface indications of the bailey wall and ditch is a ‘break in slope’ of the ground surface behind the oast house to the south of Gas Lane on the W side of the keep. However the buried remains of this bailey ditch and wall continue southwards towards the city wall. Also to the W of the keep, to the S of St Mildred’s church yard, is the site of a postern gate (one of three medieval posterns in the city walls) which is depicted in a pen and ink drawing of 1757 by Jonathan Skelton (c 1735-1759) and is in the Whitworth Art Gallery in Manchester. To the W of the bailey ditch is a grassed area. A trial trench dug in this vicinity in 1975 by Mrs P Garrard produced a number of pits and ditches. It was also shown that the area contained a sealed layer of plough soil indicating arable land use immediately outside the inner bailey after the castle was built. To the N of the keep beneath Gas Street is a further part of the inner bailey and a continuation of the bailey wall and ditch.

The area to the NNE of the Keep, where the archaeological stratigraphy is not destroyed by the Rosemary Lane car park and the make up of Castle Street, also contains part of the inner bailey, bailey wall and ditch and the remains of the Great Gate. The bailey and its defences extend into the land which is now Castle Street car park. Here finds of Romano-British mortuary urns indicate earlier use of the area.

The bailey and its defences extend S to the city walls (scheduled separately – see above). Here there are the buried and extant remains of the Romano-British Worth Gate which became the castle gate in the medieval period. On the S side of the scheduled city wall is the buried remains of the substantial Romano-British ditch which was also reused in the medieval period. This has been compromised by the construction of Rheims Way and the pedestrian underpass to the W of Castle Street but will survive to the E in the areas not affected by house cellars.

EXTENT OF SCHEDULING
The scheduling aims to protect the tower keep castle including the keep, the surviving parts of the bailey and its ditch including a sample beyond the city wall. The maximum extent of the scheduling is about 165m NW-SE by about 106m NE-SW.

EXCLUSIONS
A number of buildings and features are excluded from the scheduling; these include the Oasthouse and its adjoining building, No 28 Castle Street (Castle House) although the adjoining remains of the Romano-British Worthgate are included, 39 Castle Street, the buildings and structures in Castle Street car park including the Age Concern building; all wooden platform walk ways inside the keep, notice and information boards, service pipes and wiring, boundary walls and railings, paths, roads, tarmac hard surfaces and their makeup. However, the ground beneath all of the above features is included.

Source: Historic England

Reasons for Scheduling

The tower keep castle known as Canterbury Castle is scheduled for the following principal reasons:
* Rarity: as a tower keep castle it is a rare site type, there being only about 104 examples surviving nationally;
* Period: it is an integral part of the development of the historic defended city of Canterbury locally and of the morphology of tower keep castles nationally;
* Documentation: both the history of the castle and the history of archaeological investigation are well documented;
* Potential: there is good archaeological potential remaining for future investigation;
* Group value: the tower keep castle has group value with the adjacent motte-and-bailey castle known as the Dane John and with the abutting city walls;
* Survival: the tower keep castle survives well and the bailey survives reasonably well.

Source: Historic England

Sources

Books and journals
Bennett, P et al, The Archaeology of Canterbury Vol 1, (1982), 19-88
Websites
Canterbury Castle, accessed from http://www.canterbury-archaeology.org.uk/#/castle/4557747641
Canterbury Castle, accessed from http://www.everycastle.com/Canterbury-Castle.html
Canterbury Castle, accessed from http://castlefacts.info/castledetails/castleDetails3.aspx?uin=11598

Source: Historic England