Castle or Bishops Palace — Clonmacnoise

National Monument No. 81. Situated on the low-lying floodplain of the River Shannon which overlooks it to the N. The monastic site (OF005-004----) of Clonmacnoise lies nearby to E. In 1215 Ralph de Derevaus and Walter Reboth who held the custody of the castle of Clonmacnoise were requested to deliver it to Geoffrey de Mariscis (Cal. doc. Ire., 94). The stone castle constructed in the early 13th century comprises a rectangular, three-storey stone keep with adjoining courtyard area, built within a D-shaped earthwork (dims. 32m N-S x 37m E-W) defined by two earthen banks and a wide flat bottomed intervening fosse (Wth 5.9m). The inner bank (Wth 3.7m) is visible at NW only, while the bettere preserved external bank (Wth 6m; int. H 6.25m; ext. H 3-6m) is upstanding from E-S-SW. A possible ramped entrance feature is located at N. The keep (dims. 11.3m N-S x 19m E-W; wall T 2.2m) is constructed of uncoursed limestone rubble and comprises just the N and S walls with wall-footings elsewhere. A fore-building set laterally to the N wall of the keep and which contained the drawbridge, was reached from the wall-walk and led to the main entrance at first floor level. A vaulted support at the W end of the N wall of the keep reinforced the drawbridge. This fore-building which was illustrated by Blaymires in 1739 (Manning 1994, 18) has long since collapsed with just the drawbridge slots remaining. The first floor of the keep was lit by narrow slit opes set within widely splayed segmental arched embrasures. A spiral stone stairs in the NW angle gave access to the upper storeys. The outer courtyard or bawn area (int. dims. 16m N-S x 17.4m E-W; wall T 1.05m) lies N of the keep and is accessed via a round headed, segmental arched entrance with a gatehouse directly inside. Of this three-storery rectnagular gable ended gatehouse with attic above, the SW gable remains intact housing a garderobe at first floor level. It is lit at each level by narrow slit opes set in widely splayed segmental arched embrasures. There are no architectural features later than the 13th century in the fabric of the castle and it has been suggested that it may have been undermined and perhaps abandoned as early as c. 1300 during the period of the Gaelic resurgence (ibid. 35). Of interest are two references in the annals to the fort of 'Liseenabbey' at Clonmacnoise which was burnt on easter Sunday 1135 and which with its '47 houses both great and small' was again attacked and burnt in 120 (Ann. Clon. 194, 221). Although the location of 'Lissenabbey' cannot be positively identified with that of the later castle, it is possible that it was an earlier earthwork fortification built to protect the wooden bridge (OF005-059) over the Shannon at Clonmacnoise and later re-fortified by the Anglo-Normans. (O' Donovan 1856-7, 448; Cooke 1875, 369-73; Monahan 1886, 69; Westropp 1907, 304-6; OPW 1906-7, 8; Anon 1907, 337; Harbison 1975, 204; Manning 1994, 33-4) Castle built in the early 13th-century by the English on the site of the Fort of the Abbot (O' Flanagan 1933, vol. 1, 67). Situated on the low-lying flood plains of the river Shannon which is located immediately to the N. Rectangular stone keep with courtyard area built inside a D-shaped earthwork (diam 32m N-S; 37m E-W) enclosed by two earthen banks with wide flat bottomed intervening fosse (Wth 5.9m). The inner bank (Wth 3.7m) is only visible at NW while the better preserved external bank (Wth 6m; int. H 6.25m; ext. H varies from 3 - 6m) is not visible from W through N to NE. Possible ramped entrance feature located at N. Rectangular stone keep 3 storeys high with courtyard area situated in the SE sector of the enclosure. The outer courtyard or bawn area (int. dims. 16m N-S; 17.4m E-W; wall T 1.05m) is located to the N of the keep which is accessed via a round headed segmental arched entrance with gatehouse directly inside. This gatehouse is three storeys high with attic above. SW gable still intact with garderobe in SW angle at first floor level. The windows are narrow slit opes set in widely splayed segmental arched embrasures. The Keep (11.3m N-S ; 19m E-W; wall T 2.2m) is built with uncoursed limestone rubble with only the N and S walls surviving with wall footings elsewhere. There was a forebuilding attached at first floor level to the N wall of the keep. This structure now collapsed contained the drawbridge of which the slots survive. The drawbridge was set laterally to the N wall from which the main entrance at first floor level was accessed. Possible stairs along the W wall of the bawn gave access to the drawbridge at the NW angle of the building. This forebuilding is depicted on Blaymires drawings of Clonmacnoise 1739 (Manning 1994, 18). The main entrance gave access to the first floor which was lit by a window set in each wall. The windows were all narrow slit opes set within widely splayed segmental arched embrasures. The spiral stairs in the NW angle gave access to the ground and upper storeys. All the floors were wooden with evidence of a vaulted support externally at the W end of the N wall which would have acted as a support for the drawbridge. The architectural features and layout of site would suggest an early medieval date for the castle possibly on the site of an earlier earthwork which is referred to as the Fort of the Abbot. The lack of late medieval features would suggest that the site was abandoned before this period (Manning 1994, 35). (O' Donovan 1856-7, 448; Cooke 1875, 369-73; Monahan 1886, 69; Westropp 1907, 304-6; OPW 1906-7, 8; Anon 1907, 337; Harbison 1975, 204; Manning 1994, 33-4) The above description is derived from the published 'Archaeological Inventory of County Offaly' (Dublin: Stationery Office, 1997). In certain instances the entries have been revised and updated in the light of recent research. Date of upload: 23 May 2011