Introduction An archaeological assessment was carried out by Linzi Simpson in February 1999 in advance of a proposal to remove and replace a nineteenth-century concrete floor in the crypts of Christ Church Cathedral, Dublin. The aims of the assessment were to locate the original level of the crypts and to expose any earlier floor levels. There was also the possibility of uncovering deeper Viking levels, given the previous finding of Viking remains on the north side of the cathedral during the Wood Quay excavations. Further monitoring work was carried out by Helen Kehoe between October and December 1999 during the refurbishment.
Linzi Simpson's assessment revealed no deep archaeological levels within the crypts, and the crypt walls and piers were found to stand directly on boulder clay in shallow foundation trenches. Among the archaeological features uncovered were several post holes, which were found in the central area of the crypt, and the remains of a medieval wall, located at the west end (see plan). During the subsequent monitoring, Helen Kehoe noticed some archaeological features, most notably wall remains predating the Anglo-Norman cathedral. These wall features remain in situ, and a section may be seen through the glass window that has been inserted in the new stone-flagged floor.
Background Sitric Silkbeard, king of Dublin between 989 and 1036, is the reputed founder of Christ Church Cathedral. However, his original church was demolished by the Anglo-Normans, who began constructing the crypts, choir and transepts sometime between 1186 and 1200. In c. 1234, the prior and canons sought leave to extend and lengthen the building. In doing so, the roadway (Winetavern Street) on the western side of church was blocked and had to be diverted. The line of the original street, however, appears to have been preserved in a passageway that extended through the crypt in a north-south direction. The Dundry chamfer stops of this pasageway are still in position in the west bay of the crypts, but the passageway is now blocked.
The crypts, groin-vaulted in stone, form the foundations of the church and mirror the line of the choir, transepts and nave above. The two-phase development of the church can be identified in the stylistic break between the Romanesque and Gothic that coincides with a break in the crypts beneath. The east end of the crypt is supported by rectangular piers of black stone, each with a rough abacus beneath the springing of the vaults. These piers also have a small matching offset/footing at the base. At the west end, however, beneath the nave and following a significant fall in floor level from east to west, the piers are finer in type and have decorative Dundry chamfer stops. The difference in pier type appears to relate to the change in floors levels.
Using the crypts as foundations for the church gave rise to an instability in the building, which suffered a series of collapses in the sixteenth century. One of the subsequent repair jobs included repairs to the piers beneath the northern crossing. The strengthening works involved the laying down of lime and massive, ten-inch square oak beams, which were ‘seat doune in the ground with great vyolence.’ The current assessment has revealed that the pier bases sit on boulder clay, so it is difficult to envisage what the timbers were driven into so violently.
The cathedral was substantially ‘restored’ by George Edmund Street between 1871 and 1878. Street describes how the crypts were ‘found almost filled with rubbish, the debris of countless coffins and human remains.’ Access to the side chapel was ‘by creeping and crawling on all fours, lantern in hand.’ Street removed approximately 10,000 cartloads of material from the crypts, dumping them in large pits on the east and south side of the cathedral. One of Street’s enduring legacies is the concrete floor in the crypts that prompted the current archaeological work.
Findings Organic layer on the east side An organic layer found, 0.14 m in depth, containing a large quantity of large animal bones (including the jaw of a horse), some oyster shells and some charcoal fragments, was found along the east side of the crypts. It was sealed by a layer of loose, apparently reused medieval limestone that had been laid as a bedding for Street’s concrete floor.
Post holes Four small post holes were located in the boulder clay in the centre of the crypt. No clear pattern could be discerned, and their date and function could not be determined. The boulder clay in the vicinty was a worn surface and produced several pottery sherds of tin-glazed earthenware and fragments of red brick, suggesting that the area was a trampled surface when the concrete was poured in the late nineteenth century.
Medieval wall At the base of a pier bonded with the west wall of the crypt, the remains of what appears to be the core of a medieval wall (with the facing stones robbed out) was exposed. The core of the wall was made up of limestone mortared with a gritty, coarse, bright orange mortar. A thin deposit of mortar extended from the base of the wall on the eastern side, sealing an earthen and cobbled floor beneath. This layer of mortar probably represents the line of a demolished wall. The date and function of this ‘possible wall’ is a mystery. It lies to the west of the north-south ‘passageway’ created in the thirteenth century and must represent an earlier structure, which is a puzzle if Winetavern Street originally extended through this location.
Pre-Anglo-Norman wall remains A trench dug between Piers 2 and 3 revealed a two-phase stone structure beneath the existing late twelfth/thirteenth century cathedral. The walls appeared to represent the northwest corner of a masonry structure that was reused as a foundation for a pier in the Anglo-Norman period. The earliest phase of this wall (F10) was to the west, and it was built with well-coursed limestone blocks bonded with a distinctive gritty, off-white mortar. Two small investigative trenches revealed that the east-west return wall extended beyond the northeastern corner of Pier 3 for 1.2 m; it was not possible to establish if there was a north-south return.
A later phase of development was represented by a clay-bonded wall (F6) built against both the west and north faces of F10. This later wall was built with large limestone blocks bonded with a mid-brown, sticky clay. It was one course high and had been cut into the boulder clay. The remains of F6 and F10 appear to have been deliberately used as a foundation base for the building of the crypt.
Paving The remains of a section of various-sized clay-bonded paving stones were uncovered at the base of the foundation stones (F5) for Pier 2. They extended approximately north-south and were loosely adjacent to the baseline of F5. The outer, east-facing section appeared to be faced with a row of 'edging stones' that formed a distinctive north-south line corresponding to the west face of F10, forming a possible channel or drain feature.
Southwestern recess In the southwestern recess, or alcove, a well-used beaten floor surface was revealed beneath a layer of modern clay and sand. The surface appeared to comprise mainly extremely hard, beaten clay with some grit inclusions, and there was some evidence for the presence of decomposing flagstones adjacent to the base of two black-stone steps that led up to an in situ defunct window on the south wall. This floor may form part of the remnants of a medieval public-access laneway that remained open even after the cathedral was extended westward in the mid-thirteenth century but that eventually was blocked up.
The crypts, groin-vaulted in stone, form the foundations of the church and mirror the line of the choir, transepts and nave above. The two-phase development of the church can be identified in the stylistic break between the Romanesque and Gothic that coincides with a break in the crypts beneath. The east end of the crypt is supported by rectangular piers of black stone, each with a rough abacus beneath the springing of the vaults. These piers also have a small matching offset/footing at the base. At the west end, however, beneath the nave and following a significant fall in floor level from east to west, the piers are finer in type and have decorative Dundry chamfer stops. The difference in pier type appears to relate to the change in floors levels.
