Archaeology at Glastonbury Abbey on-line
Trustees of Glastonbury Abbey, 2007. (updated 2010) https://doi.org/10.5284/1000292. How to cite using this DOI
- Archive introduction
- Great Church report
- Lady Chapel report
- St Patrick's Chapel report
- Undercroft report
- Topographic Survey
- Photogrammetric Survey
Data copyright © Trustees of Glastonbury Abbey, Individual Authors unless otherwise stated
This work is licensed under the ADS Terms of Use and Access.
Primary contact
Dr
John
Allan
Exeter Archaeology
The Custom House
The Quay
Exeter
EX2 4AN
England
Resource identifiers
- ADS Collection: 770
- DOI:https://doi.org/10.5284/1000292
- How to cite using this DOI
Undercroft
Overview
The earliest deposit encountered, about 0.25m below the modern grass of the cloister walk, is a layer of mixed clay which has yielded a few sherds of 10th- to 12th-century pottery. No occupation horizons are visible in it; a likely explanation is that this was earth dumped at the lower, southern, side of the cloister to raise the ground as part of the process of creating a large level square area for the new Norman cloister.
This dump was overlain by a hard mortar floor which had been heavily burnt in situ. Whilst there are always snares in matching archaeological deposits to known historical events, this probably represents the devastating fire of 1184 which burnt down most of the abbey and the fine Norman buildings around the cloister. A radiocarbon determination supports this interpretation, yielding a date of AD 1160-1225 at 68.2% probability and 1050-1270 at 95.4%. The burning was overlain by a dump of building materials including mixed clays, mortar, plaster (including one large piece) and slate (the last presumably from the roof of one of the Norman claustral buildings) but with no building stone and little burnt debris. This debris may represent the demolition of timber buildings damaged by the fire. The top of this layer sat immediately below modern topsoil. The excavation showed clearly that 12th-century deposits lie immediately below the modern ground surface of the cloister.
Judging by the doorways and other features in the eastern cloister walk, the level of the later medieval floor must been only slightly below the level of modern grass. It evidently consisted of inlaid floor-tiles, many loose fragments of which were found in 1910; the floor was probably stripped at the Dissolution.
Two late medieval features were seen in the excavation. First, a broad but shallow stone-lined drain ran down beside the southern side of the Chapter House and through the cloister walk, draining into the cloister garth. This feature was more fully exposed by Bond around 1910; he showed that its course within the cloister curved to avoid the late medieval buttresses projecting from the south cloister walk, showing that the drain was contemporary with or later than them. Reused architectural fragments formed some of the cover stones in the section opened in the present excavation.
Second, a narrow trench lined with vertically set narrow slabs was found running down the eastern side of the cloister walk, beside the front wall of the dorter undercroft. Only a short length survived; a further section to the south had been exposed by Bond in 1910 but had collapsed by the time his trench was backfilled, and now consists of loose slabs. This had no flooring stones; it probably represents the trench for a lead pipe rather than a drain. Most of its intersection with the broad drain had been removed by Bond, but sufficient was found to show that the broad drain was the later feature.
The line of the front wall of the dormitory undercroft was represented by a mass of small rubble, no doubt representing the top fill of its robber trench. This was not removed. Finally, the excavation area was criss-crossed by earlier excavation trenches, the earliest attributable to Bligh Bond's work of c. 1910; the later trenches may relate to his later excavations or those of his successors. Most of these are very shallow (at least in relation to the ground surface of the displayed monument). If they are typical of the early excavations at the abbey, extensive areas of archaeological deposits will survive in the parts of the site which have previously been excavated.
