The little strip of land between Museum Street and Cowdray Crescent where the War Memorial stands is an archaeological treasure trove. Here, buried beneath the shops and offices, lies precious remains of important monuments of Colchester’s Roman and Norman past.
These include a massive Roman foundation, over four metres wide, which carried a once impressive facade and a large monumental arch leading to the massive Temple of Claudius. These remains are exceptionally well preserved because they lie under the earthen bank of Colchester castle. But there is much more. Don Shimmin, who has been following recent building works in this important part of the historic town, explains how some puzzling fragments of foundation in Museum Street are likely to be part of a medieval barbicon – a defensive structure which helped protect the castle’s main entrance.
The area around Museum Street and Castle Bailey is of exceptional archaeological interest. The southprecinct wall of the Temple of Claudius has been investigated several times over the years. Less well-known are the remains of the medieval gateway leading into the castle bailey. More evidence for this has come to light recently during the refurbishment of Toto’s restaurant.
Monumental temple precinct wall
Evidence for the Roman south precinct wall was uncovered in 1931, 1953 and 1964. The wall was fifteen foot wide (4.6 m) and consisted of a large arcaded screen, which originally was probably over 8 m high. The temple precinct was entered through a monumental arch in the middle of the south wall, and to the south lay a series of east-west drains. Parts of the entrance and of one of the Roman drains were exposed a few years ago in 2006 (see The Colchester Archaeologist 20, 16-7).
The site trenched in 1964 (97 High Street) is due for redevelopment in the near future. In advance of this, a number of trial holes were dug onthesitebythecontractorsandweremonitored by CAT. The remains of the south precinct wall were found in good condition just over a foot below the modern yard surface, to the rear of the High Street frontage. From the deposits overlying the precinct wall, and probably derived from it, came fragments of building materials including a piece of Purbeck marble and several unusual Roman bricks. Plans for the redevelopment of 97 High Street are being adjusted to avoid damage to the wall and to minimize the impact on the other archaeological remains on the site.
One of the reasons why the south precinct wall survived so well was because it was ‘insulated’ by the Norman rampart which was piled-up on top of it. The bank was surmounted by a curtain wall, which was probably built in the 12th century and replaced an earlier timber palisade. Remains of this wall were destroyed by later activity, although it was mentioned by the early antiquarian Philip Morant. He wrote in 1748: ‘The Bailey was formerly encompassed on the south and west sides by a strong wall in which were two gates. That on the south was the chief.’
One side of the south or Dunbarr gate was found under the pavement in the northern half of the Museum Street in 1986, during archaeological excavations in advance of the resurfacing of the street (see The Colchester Archaeologist 1, 5 & 21). It consisted of the base of a wall which survived at least 4 courses high and had several well-defined faces at right-angles to each other. The wall foundation lay only a foot or so below the modern ground level and extended under the adjacent building (Toto’s).
The excavations in 1986 were limited in scale due to the short time available and restrictions over the depth it was possible to dig to. Access was only possible on a piecemeal basis, and the street was riddled with modern service trenches. Nevertheless a series of extensive foundations was uncovered along the length of Museum Street, often extending under the buildings fronting onto the street. The foundations were constructed of a yellowish sandy mortar and incorporated fragments of reused Roman brick/tile, septaria, and occasionally greensand, often with Roman mortar adhering to them.
A complete refurbishment and enlargement of Toto’s restaurant is taking place in 2009-10 and is being monitored by CAT. The work includes the underpinning of the structure, much of which is timber-framed and dates back to the 17th century. For this the contractors hand-dug a number of trenches, and they also lowered in places the level of the deposits under the modern floors. This gave CAT the opportunity to record more of the medieval foundations seen in 1986, including the previously unseen part of the south gate.
In the trenches in the northern part of Toto’s a thick sandy deposit was reached roughly 1 m below the modern floor level. This was probably part of the medieval rampart around the castle bailey. A burial was disturbed nearby. This perhaps dated to the sixteenth or seventeenth century when the bailey was used for burials, mainly for prisoners housed in the keep. A small post-medieval brick cellar with a barrel-vaulted roof was also discovered.
One of the trenches on the street frontage in Toto’s was dug to a depth of 3.4 m, the lower 2 m or more of which appeared to consist of a medieval robber trench. This was probably left after the building materials had been robbed from a large Roman foundation, only 5 m to the north of the south precinct wall of the Temple of Claudius. Among the finds from the robber trench were three fragments of marble.
No trace was found of the other side of the medieval south gate in 1986 on the opposite side of the street. However this position accords well with that of the ‘Castle Bayley gate’ described in a document of 1683. Perhaps the remains of this side of the gate lay just to the east of Museum Street within the property described in the 1683 document. The gate was called the ‘Dunbarr gate’ on a map dated 1709. This name was probably not of great antiquity, but derived from the Dunbarr family who leased property in the area in the late 17th and early 18th centuries.
Newly-discovered castle barbican
Several more large foundations were uncovered in the southern half of Museum Street in 1986, but are less easy to interpret. They probably formed abutments for a bridge over the bailey ditch and/or a passageway leading up to the gate. Such a passageway is what appears to be shown in the map published by Speed in 1610. This whole group of foundations probably formed part of an outer barbican at the main entrance into the castle bailey. Barbicans were defensive outworks designed to protect an entrance to a castle or bailey, and were often reinforced with towers.
An inner barbican with two D-shaped towers was added in the thirteenth century to protect the main entrance to the castle keep itself. The remains of this were uncovered in 1931-3, along with other forebuildings including a chapel and a hall. The foundations of the inner barbican and chapel are still visible today on the south side of the castle keep.
Little archaeological dating evidence was recovered for the construction of the foundations in Museum Street, although documentary evidence suggests they date from the late 12th or early 13th century. The outer barbican had probably been largely demolished by the mid-17th century, although the 1683 document and the 1709 map suggest that the gate survived in some form until this time.
The 1986 excavations were funded by Colchester Borough Council. The watching brief at Toto’s was funded by Mr F Mussi and that at 97 High Street by Flying Trade Group plc.
Feature (without its illustrations) by Philip Crummy of the Trust: from the Colchester Archaeologist magazine, no 23, 2010. Past issues of the magazine are available from the Trust. Some can be read online at http://cat.essex.ac.uk