Summary

The monument includes part of a Romano-British bath house and a chalk construction and vaulted chalk piers dated to the C11 to C12.

Source: Historic England

Details

Part of a Romano-British bath house complex dated to the early-C2 AD and a medieval chalk construction and a series of vaulted chalk piers of C11 to C12 date.

The site at the junction of Borough High Street, London Bridge Street and Railway Approach in Southwark includes a small part of Roman London S of the River Thames. Historically it lies towards the upper peak of the northernmost of the islands which existed in the River Thames at that time.

The excavation area, aligned NE-SW, was divided into three parts: area A1 at the NE end of the site was 5.35m by 10.8m, area A2, which adjoined A1, was 5.86m by 11.22m and area B, to the SW, was 11.15m by 6m. The combined sites were situated at the junction between Railway Approach/London Bridge Street and Borough High Street. For ease of description the site can be considered broadly as comprising a N part (A1 and A2) and a S part (B).

The excavation revealed a part of the buildings which lay close to the east side of the main Roman N-S street through the settlement (Road 1).

LATE C1 TO EARLY C2
The area of the monument appears to have undergone some ground consolidation in the early Roman period, evidenced by Mesolithic or Neolithic flints found in later deposits. Consolidation was followed by some industrial activity in the southern part of the excavated area which included the production of leaded copper alloy and iron working.

Towards the middle and S end of the site is the earliest evidence of building comprising brickearth partition walls of structures fronting onto the main Roman road (Road 1) through the town to the W and a subsidiary road leading off it. The building fronting the subsidiary road is associated with copper working and continued in use until the early C2. After this phase the ground level here was raised. The industrial activity continued in the northern and central parts of the site until towards the end of C1 it reduced and domestic occupation predominated. This is evidenced by opus signinum (consolidated crushed terra cotta tile mixed with lime or clay mortar) surfaces and refuse pits. The same pattern of reduced industrial activity also applies to the southern part of the site.

N PART OF THE SITE INCLUDING THE BATH HOUSE AND C2 OCCUPATION
The construction of a high status masonry building dominated the northern area of the excavation. This building or complex of buildings is constructed of Bessalis brick walls on ragstone foundations and is thought to date to the early C2 although the full depth of the foundations was not able to be examined because of project depths. This building, identified as a bath house, includes two complete rooms and parts of two other rooms adjoining them to the NE, all of which appear contemporary. The remaining parts of the NE rooms lie outside the excavated area and the complete rooms lie to the SW of them.

The largest complete room lies on the SW side of the site; it is circular in form with a thick insulating outer wall (0.7m wide) overlain by a brick floor and an inner curvilinear wall (0.45m wide) constructed against the outer wall. Internally it is about 4.9m diameter and externally to the outer edges of the walls about 7m in diameter. Walls are about 0.3m-0.4m high. Limescale residues on the floor indicated damp conditions were present when the room was in use. The inner wall ‘lips’ over the floor surface and had been coated with opus signinum indicating a requirement for waterproofing. The appearance of the plan of the structure and the limescale residues indicate that it is a Laconicum, or sweating room. The inner curvilinear wall would have supported seating which has been removed by robbing or later intrusions. The second complete room, to the E of the Laconicum measures 4m by 2.4m. Dumped deposits dating to the late C2 to early C3 suggested that parts of the complex had fallen out of use by this time.

The two incomplete rooms at the far NE end of the site are part of this bath house complex, but their function is not identified with certainty. They measure 5.25m by 1.8m and 4.3m by 1.6m. They contained numerous copper objects (including a spatula) and pottery no later than AD 160. Both rooms were modified at least twice; in the mid/late C2 and again in the late C2. Modifications include the insertion of a drain into one of the rooms. Robbing and levelling the ground in both rooms occurred in the late C2 and there are indications that the original wall facings were removed and an opus signinum floor and flues added. The addition of the opus signinum floor over debris similar to that from the Laconicum indicate that by the C3 this part of the complex was no longer used as a bath house, but continued with an unknown alternative function.

The complete room, on the SE side of this N part of the excavation and which abuts the Laconicum on its E side, is less well preserved since much of the room is truncated by later intrusions. Scarring on the internal face of the N wall of this building shows that floor levels had existed. The truncation makes identification of features difficult, but the room contains partially identified pits and levelling deposits, which excavation shows contain C1 to mid C2 material, although these features may perhaps belong to an earlier phase pre-dating the complex. The function of this room is unknown.

S PART OF THE SITE IN C2 TO C4
At the SW end of the excavation elevation of levels comparable to those in the excavation further N and the construction of a masonry structure in the NW part of Area B indicates widespread development taking place in the early C2. Towards the mid/late C2 seven distinct areas or rooms were established in this S part of the excavated area. Because of the difference in construction techniques it is likely that the three western rooms with ragstone foundations belong to a different complex from the three rooms to the E. The final area, at the far SW end of the excavation may have been a room or more likely an open space since a multi-phase cess pit is present here.

In the W complex the rooms may have abutted each other. Opus signinum surfaces occur in each room. The levelling layers below this are dated to AD 160.

In the E complex the rooms are thought to define areas within a separate timber framed building partitioned by beamslots and several opus signinum surfaces. Slumping of levelling material and mortar suggests several phases of rebuilding in the C2 to early C3.

In the late C3 and C4 there appears to have been extensive robbing of the bath house and abandonment. However in the W complex of rooms at the S end of the site there is evidence of possible later phases of occupation within the footprint of the earlier structure.

MEDIEVAL C11 TO C12
The site underwent some development in this period; this comprised two areas of activity; a chalk construction in the N part of the site at the E limit of area A1, and a series of vaulted chalk piers in the S part of the site built across the S limits of area B. Both constructions utilised Roman tile and the former, which is directly over the Roman foundations, is of two phases of construction within a short period of time of each other. It is not clear if the chalk piers of the two areas relate to each other, but the vaulted piers lie along the boundary of St Thomas’s Hospital precinct as depicted on later maps. It is therefore conceivable that the piers relate to the medieval hospital building.

EXTENT OF SCHEDULING
The scheduling aims to protect the full known extent of the Roman bath house and the medieval chalk construction and vaulted chalk piers. The maximum extent of the monument is about 22m NE-SW by about 20m NW-SE.

EXCLUSIONS
The infilled soil, the overburden, the modern foundations and services and the structures above ground level are all excluded from the scheduling. However the ground below the infill of the excavation and the existing excavated structures are included.

Source: Historic England

Reasons for Scheduling

The Roman bath house and associated medieval remains of St Thomas' precinct at 11-15 Borough High Street, Southwark, London are scheduled for the following principal reasons:
* Period: the bath house is characteristic of its period;
* Documentation/finds: the site was excavated to professional modern standards and a full record of the stratigraphy and artifacts was made;
* Survival/condition: the excavation ensured that archeological remains were left in situ and some parts of the site were deliberately left un-excavated;
* Potential: the excavation ensured that archaeological potential remains in the site;
* Fragility/vulnerability: the remains of the bath house are fragile and potentially vulnerable to damage;.
* Group value: for its group value with other Roman finds from London in general and Southwark in particular.

Source: Historic England

Sources

Books and journals
Cowan, C, Seely, F, Wardle, A , Westman, A, Wheeler, L , Roman Southwark settlement and economy Excavations in Southwark 1973-91, (2009), 1-176
Drummond-Murray, J, Thompson, P, Cowan, C, Settlement in Roman Southwark Archaeological excavations (1991-8) for the London Underground Limited Jubilee Line Extension Project, (2002), 1-149
Websites
Living in Roman London, Londinium Lite - archive of the Museum of London, accessed 22/12/2014 from http://archive.museumoflondon.org.uk/Londinium/analysis/publiclife/structures/16+baths.htm
Other
Oxford Archaeology-Pro-Construct Archaeology '11-15 Borough High Street and 2 London Bridge Street, London Borough of Southwark' (Post Excavation Assessment) (2013)

Source: Historic England