18.3 : King John’s Castle, Limerick E534/93E082
Site location: NGR 15770/15770 SMR LI 005-017
Fig.18.3.1: Location map of King John’s Castle, Limerick [OSI]
King John’s Castle is a magnificent medieval fortification located along the western side of a large island in the River Shannon (Fig. 18.3.1), where historic settlement at Limerick, first established in Viking times, was concentrated. The castle forms a large, nearly square enclosure dating from the thirteenth century, much of which is well preserved today. The surviving elements of the castle include three massive angle towers, two along the edge of the Shannon, forming the north-western and south-western corners of the enclosure and a third at the north-eastern corner. The twin-towered gatehouse, the earliest of its type in Ireland, is probably the castle’s most impressive feature. Part of a bastion added to the south-eastern corner in the seventeenth century remains intact.
Plate 18.3.1: King John’s Castle. General view of site looking north
Plate 18.3.2: King John’s Castle Undercroft remains.
In the thirteenth century, the walls at Limerick were rebuilt and extended and the castle was incorporated within the defences of the northern half of the city, known as ‘English Town’. In 1751, a large infantry barrack was constructed inside the courtyard. The barrack was enlarged in 1793, resulting in the demolition of the eastern curtain wall and much of the bastion, creating a substantial parade ground on the eastern side of the castle. In 1922 the British military finally withdrew and the castle remained closed for the rest of the decade. In 1933 the corporation leased the courtyard from the Office of Public Works for the construction of municipal housing. This resulted in the demolition of much of the castle barrack, prior to the construction of twenty-two houses in four terraces.
This state of affairs prevailed until 1988 when a plan was devised for the restoration of the castle as a National Monument that envisaged the complete removal of the terraced housing. In early 1990 demolition commenced and archaeologists began to uncover the foundations of the eastern curtain wall of the castle, together with remains of the northern flank and eastern face of the bastion. Archaeological excavations on this area continued until September 1991. The excavated area (Site 1) measured c. 47.5m north-south, extending from the standing north-eastern tower of the castle to the standing southern wall of the bastion. The excavation width (east-west) varied between 17m and 30.5m, straddling the line of the eastern curtain wall and including the whole interior of the bastion, as well as a limited area outside the eastern face of the bastion. The original project design involved the total reconstruction of the eastern curtain wall and the bastion. Owing to the diverse nature of the discoveries made in the course of the excavation and the problems of how best to keep them on view to the public, it was ultimately decided that the entire site should be spanned by the construction above it of a boldly designed visitor building. This interpretative centre was formally opened in October 1991, finally launching King John’s Castle as Limerick’s flagship tourist attraction.
In the summer of 1993 Shannon Heritage Ltd, managers of the castle, in conjunction with FÁS, decided to set up an archaeological research project in the castle. The aim was to reveal more structural remains within the courtyard that could be displayed to visitors, and to gain more information about the origins and development of the castle. Two substantial new sites were established (Sites 2A and 2B), and excavation continued for a further season in 1994. Site 2A was located to the rear of the gatehouse, with maximum dimensions of 15.3m (east-west) by 15m (north-south). The main objective was to establish the nature of a demolished extension on the courtyard side of the gatehouse. Site 2B was located next to the western curtain wall, with maximum dimensions of 32.5m (north-south) by 23m (east-west). The intention here was to reveal any surviving evidence for the basement of a large storehouse building, dating from the late thirteenth century, but demolished 500 years later. This site included the area around the castle’s watergate at the base of the curtain wall. Undisturbed boulder clay was reached along the eastern side of Site 2B in 1995 at a depth of 6m below the courtyard of the castle.
Another excavation took place along the southern side of the castle in 1995 (Site 3). This came about in connection with a proposal by Shannon Development to create a tourist facility called Castle Lane, incorporating a theme tavern and function room, as well as providing a new location for the city museum. There was considerable archaeological impact involved in the project, as the proposed development was to be located very close to the southern curtain wall and the bastion, much of it coinciding with the line of the castle’s thirteenth-century ditch. As the Shannon Heritage/FÁS project was well established in the courtyard, arrangements were made to open a large site at Castle Lane to assess the evidence for the castle’s outer defences and to establish how much further archaeological work was needed in advance of construction work. Site 3 was located in the angle formed by the southern curtain wall and the western flank of the bastion. It measured c.18m (north-south) by 12m (east-west). Excavation took place throughout much of 1995, ending in early 1996. Further work on the Castle Lane site was undertaken in January 1997 in the form of three large test cuttings (3A, 3B and 3C), followed by further hand-excavation and monitoring during the construction of the Castle Lane development in the latter part of 1997, coming to a conclusion in May 1998.
The complete run of excavations at the castle from 1990 until 1998 has contributed immensely to our understanding of the site. The archaeological record can be divided into a number of distinct phases of activity:
(1) Pre-Norman evidence
The primary occupation levels exposed at the northern end of Site 1, as well as in Sites 2A and 2B, indicate considerable activity, in the form of dense arrangements of pits, post-holes, stake-holes, etc. Part of a Hiberno-Norse sunken-featured structure (SFS 5) was revealed in Site 2A, but could not be excavated in full. The most impressive feature was a 2.3m-wide limestone road revealed in Sites 1 and 2B, aligned east-west, which bisected the courtyard of the castle, climbing from the river’s edge to the west across the much higher ground adjacent to Nicholas Street to the east. An intriguing limestone revetment pre-dating the road was discovered in Site 2B.
(2) The Anglo-Norman ringwork castle (1175-6)
The main evidence for a ringwork-type fortification came to light during the Site 1 excavations in 1990-1. Stunning remains of the structure were exposed in the north-eastern quadrant of the castle, consisting of a clay bank secured by a rough limestone revetment. The retaining wall was placed directly on top of the pre-existing limestone road. The rampart was defended by an external ditch, measuring c. 11.4m wide by up to 2.8m deep. Part of the northern line of the ringwork bank was exposed on Site 2A and more of its southern extent on Site 2B.
(3) The restored authority of Domnall Mór Ó Briain (1176–94)
Three sunken-featured structures (SFSs 1–3), post-dating the ringwork ditch, were excavated on Site 1. These structures had stone-lined entrance corridors on the eastern side. SFSs 1 and 3 consisted of one-roomed chambers, but the interior of SFS 3 (the western half of which was excavated in 1995 on Site 3), was divided into two rooms. The floors did not include a hearth, suggesting that the structures may have been used for storage rather than as living accommodation. A similar structure on Site 2A with decayed internal timberwork (SFS 4) was internal to but post-dated the Anglo-Norman ringwork. This was a one-roomed structure, but there was no stone-lined entrance passage. A long post-and wattle fence was inserted lengthwise into the partially infilled ringwork ditch. It was connected to a separate post-and wattle fence aligned north-south. Another sunken building (SFS 6) was excavated on Site 3, which was smaller than those revealed inside the courtyard.
(4) The development of the stone castle in the thirteenth century
Excavations on Site 1 revealed substantial foundation remains of the eastern curtain wall. The wall was built as a series of five distinct sections of limestone masonry, extending southwards from the north-eastern corner tower. The fourth section was built without footings and was entirely removed during the demolition of the wall. At the southern end of Section 5, the masonry formed an angle with the southern curtain wall, indicating that there was no round tower at this corner before the construction of the bastion in the seventeenth century.
The remains of a pair of very solid limestone walls projecting from the back of the twin gate-towers, flanking the entrance itself, were excavated on Site 2A. These defined what would have been a square extension with a vaulted ceiling behind the gatehouse, providing greater depth and protection for the main gate in the medieval period.
Without doubt the most spectacular feature of thirteenth-century date was the undercroft of the castle’s great hall or storehouse, which came to light on Site 2B. The undercroft of the building had been backfilled around 1790–1800 with vast quantities of heavy rubble following the demolition of the superstructure by the British military. What emerged in the course of the work was the well-preserved basement level, measuring c.24m (north-south) by 15m (east-west) by up to 5m in depth below the courtyard. The most impressive features of the undercroft included four splayed arrow loops overlooking the river, a large doorway in the northern wall, leading into an unexcavated ante-chamber, and a fine sandstone window in the eastern wall, next to a blocked doorway. A stout buttress was built against the exterior of its eastern wall. Limited excavation below the floor level of the undercroft exposed the footing of the western curtain wall, at a depth of 8.7m below the courtyard level. The building was framed along the eastern side and southern end by the retaining walls of a wide access corridor, established in the year 1297 that connected the watergate with the courtyard. A long stretch of the original corridor masonry was excavated, with a maximum surviving height of 1.7m. Once the corridor was constructed, the courtyard was levelled with bulk clay infill. A gold ring was recovered from this material (Whyte 1996).
A complete section of the castle ditch was excavated on Site 3 in 1995-6, containing thick clay deposits of medieval date at the lower levels. Limited evidence for the medieval ditch was revealed on Site 1, underneath the walls of the seventeenth-century bastion.
(5) Early seventeenth-century improvements
The weak south-eastern corner was fortified in 1611 by the addition of an artillery platform or bastion. Site 1 excavations exposed the foundations of the eastern wall, c.16m long, surviving to almost 4m in height. The northern flank was 8m long, and incorporated a sallyport of finely dressed limestone blocks. Evidence for the re-cutting of the castle ditch in 1611 was exposed on Site 3.
(6) The siege of the castle (1642)
The remains of four mines and four countermines dating from the siege of May to June 1642 were excavated on Site 1, along with part of a trench dug by the castle’s garrison. Two significant features dating from the siege were discovered on Site 2A: a burial pit and a large pit dug in the gate passage to help defend the courtyard in the event of a storming attack on the main gate. The archaeology of the siege has been published in full as a monograph (Wiggins 2000).
(7) Later seventeenth-century improvements
In the 1660s changes were made to the corridor around the undercroft of the storehouse. The eastern extent was backfilled and sealed, and a new retaining wall with a sloping face was built along the southern side, with a maximum surviving height of 3.4m. The brick floor of a building adjacent to the eastern side of the storehouse, possibly dating from the 1690s, was excavated on Site 2B. The castle ditch was re-cut several times between c.1651 and 1691.
(8) Castle Barrack material (1751-1922)
Mortared limestone rubble foundations relating to the barrack buildings were recorded and removed on Sites 1, 2A and 2B. A limestone partition inserted into the Site 2B undercroft may date from the start of the barrack era in 1751. Forty years later the storehouse was demolished, and its backfill contained a large volume of pottery and numerous metal objects. In the watergate corridor, many limestone steps and cobblestones, a vaulted ceiling and other masonry survive from this phase.
Whyte, E., 1996 ‘Church property dumped in Limerick Castle’, Archaeology Ireland, 35, 14–16.
Wiggins, K., 2000. Anatomy of a Siege: King John’s Castle, Limerick, 1642. Wordwell, Bray.