Glastonbury; The Mound

Description

A mound with an apparent ditch, known as Glastonbury Castle, was earlier described as a motte and bailey (VCH).
The mound is somewhat circular in outline and measures about 100yds in diameter. The top is flat and roughly oval in shape with the long diameter N-S and about 160 ft. The mound is more clearly defined to the N and E where is rises abruptly to a height of about 12 ft. There is a distinct shallow ditch around the mound. The name 'castle mound' is probably very recent.
An excavation trench (PRN 29183) revealed a layer of clay spread over the mound, which is believed to have been spoil from the construction of the canal (PRN 11841). Below this was an occupation deposit overlying natural yellow and grey clays, the latter indicating a natural origin for the mound. Finds included Romano-British and Medieval pottery including a 'large two-handled amphora of buff-coloured ribbed ware'. There were also objects of antler, iron and bronze, animal bone and some flint cores. There was evidence that a wattle and daub building destroyed by fire had occupied the site. The surrounding ditch is of doubtful date and appears to be later than the time of habitation, as it contained neither occupation material nor any of the black earth formed at the time. It was suggested that it might even be natural caused by the slipping of the clay (Bullied and Morland).
In 1966 the site was visited and found to lie on a slight spur on the edge of the low lying moors. At the end of the spur a flat oval area is bounded by an apparently artificial scarp and a silted ditch. There are no other significant surface features (OS record card).
The mound consists of a roughly oval clay plateau 40m x 30m at the summit forming an "island" standing c5m above the moors. It was levelled in 1972 to make way for factory redevelopment.
In 1969 Poyntz-Wright opened a trial trench on the S side of the mound (PRN 29187) in which were discovered a few C11-12 potsherds and some stonework. These led him to identify the site with the 'castellum' mentioned in an account of the buildings of Abbot Henry of Blois (1126-71) but the limited nature of the work could not confirm this identification.
In 1971 a site to the S and adjacent to the mound was redeveloped for industrial use, and a machine-excavated section a few metres from the S-SW side was observed and recorded (PRN 29186). In this the remains of a possible iron-working furnace was noted, but there was no dating evidence.
In September 1971 rescue excavations (PRN 29185) were undertaken, in advance of the destruction of the mound for industrial development, by Glastonbury Antiquarian Society and the Department of the Environment. Area I on N part of the summit, II and IIa on the SW side. The stratigraphy in trench I was as described in the 1926 excavations but no evidence was found to confirm the deposition of the clay as part of the canal works. A hearth was one of the few features recognised in the dark occupation layer but this layer produced most of the finds, which mostly dated to C10-12. Six groups of stones forming 'cairns' were found apparently randomly spaced across the trench. The ditch was examined in an extension to trent I and was found to cut through the occupation layer. It was 0.8m deep and 1.8m wide but contained no datable finds. A few features were found below the occupation layer cutting into the natural clay of the mound. These included post-built structures and a pit containing a metal-working hearth.
Trenches II and IIA were sited close to the location of the furnace seen in the earlier watching brief (PRN 29186). The clay layer was recorded and contained C11-12 pottery, animal bone and slag. Below this, the occupation layer contained more clay and appeared to have been partly baked.
When the mound was finally levelled in 1972 a watching brief (PRN 29188) was maintained by local volunteers. Further finds were made of metalworking debris and pottery, and it appeared that the previously unexcavated areas of the top of the mound resembled those recorded, with scatters of postholes and finds.
The bulk of the pottery was of C10-12 date with a few earlier sherds. Roman pottery spanned the whole period with a wide variety of types present. Eight sherds of post-Roman imported Bii type amphora were recovered. The iron working debris indicated both smelting and smithing had taken place on the mound and appeared to be associated with the medieval pottery. Domestic and wild animal bones were recovered, the latter including deer and beaver (Carr).
Now totally obscured by modifications caused by development of the Beckery Industrial Estate. The SE side of the site is still just discernible and has been topsoil stripped, exposing the yellow clay defined by Moreland. The other sides have been totally obliterated by a garage and warehouse. Only modern finds seen when field walking. (Somerset HER)

Comments

The historical record of a castellum at Glastonbury, plus a lot of erroneous assumptions about what a castellum was, seems to be the sole reason for identifying this mound as a motte. It seems fairly clear the Abbot's castle was his residence in the Abbey.