Trial trenching at the former HMP Gloucester has revealed layers of the site’s history, from its early medieval beginnings as Gloucester Castle to its transition into a county gaol.
Since the prison closed in 2013, the site has been tagged for redevelopment and, in advance of construction, Wessex Archaeology carried out some preliminary excavations on the site this past February.
Previous archaeological work at the prison had already confirmed the location of the medieval keep and a few other buildings that would have formed part of the castle complex; the castle was an important English stronghold before the Second Barons’ War (1264-1267) and the subsequent invasion and conquest of Wales. After this, the castle was no longer needed for border protection and it was repurposed as a gaol during the late medieval period, continuing to be used as such for the next eight centuries. In 1787, though, the last standing remains of the original buildings were demolished so that a new, purpose-built county gaol, designed by William Blackburn, could be constructed.
But, even after these previous archaeological investigations, significant questions remained about the overall layout of the castle. The recent trial trenching by Wessex archaeologists has helped uncover more of the castle’s footprint, including the west wall of the inner bailey, which appears to have been significantly robbed out – the stones were probably used in roads during the post-medieval period. To the north of the keep, a substantial wall was revealed. So far it is unclear what it was for, but it may have been the north wall of the inner bailey or possibly another large building that was next to the keep. Further work on the site as the development progresses may provide further clues.
Additionally, for the first time, evidence of the castle’s use as a late medieval and post-medieval gaol was discovered, including the foundations of a possible gatehouse, which can be clearly seen on Johannes Kip’s Prospect of Gloucester (1712), as well as the brick footings of what may have been a 17th-century bridewell. Further remains of Blackburn’s 18th-century gaol were also discovered, such as part of the massive perimeter wall, the main H-shaped gaol block, and part of the octagonal Clerk of Works house, which was built into the perimeter wall in the middle of the 19th century.