Gloucester’s medieval castle comes to light at Quayside House

Cotswold Archaeology’s watching brief on development works next to the newly finished Quayside Community Diagnostic Centre, in the south-west of Gloucester city centre, has revealed significant archaeological remains relating to the medieval castle and later land use. The watching brief related to groundworks enabling the installation of mobile MRI and CT scanning units, owned by the Cobalt Health medical charity and operated by NHS staff.

The development site in relation to Gloucester’s medieval castles
The development site in relation to Gloucester’s medieval castles

The development site is located within the broader Blackfriars area, which is currently undergoing large-scale redevelopment. This area is of considerable interest, occupying ground between the Roman defences and the River Severn to the west – the course of which has changed considerably over the centuries. The original Norman motte-and-bailey fortification on Barbican Hill lay about 75m to the south-east, while the 12th century castle which replaced it was immediately to the south/south-west.

Masonry remains of the castle (stone) and more recent remains (brick) revealed in recent archaeological works, beneath the basketball court of the former HMP Gloucester.
Masonry remains of the castle (stone) and more recent remains (brick) revealed in recent archaeological works, beneath the basketball court of the former HMP Gloucester

Nothing can now be seen above ground of the castle or its moats; its site was partly taken over for the city’s historic prison which opened in 1792, while 19th and 20th century expansion of the city has removed all other traces. Much survives below ground, however, and numerous archaeological discoveries have been made in this area since the start of the 19th century. These began with the report of a ‘boat’ in 1805, and have included waterfront structures and buildings of both Roman and medieval date. Structural remains of the castle are known to survive within the area of the prison.

A number of trenches were observed and despite the limited, ‘keyhole’, observations that these allowed, they still provided an interesting insight into the medieval and later archaeology of this area.

The most significant finding was of medieval structural remains. These walls are interpreted as forming part of a masonry causeway or bridge structure which provided access to the castle across its inner defensive ditch. This causeway continued north-east onto Castle Lane, which connected the castle to Westgate Street; this lane survived into the 19th century but has since been destroyed. Evidence for the subsequent demolition and robbing of these walls was also identified, as was the infilled castle ditch.

We also uncovered later phases of the site. These principally comprised cultivation soils of the Castle Gardens, which occupied this area from the later 18th century through to the mid 19th century. In addition, a stretch of Post-medieval wall relating to the gardens was identified, which corresponds to a boundary shown on early and mid-19th century maps. Elements of the former Castle Lane were also seen.

Later development of the site has caused much ground disturbance – in previous work we encountered the remains of a former early 20th century engineering works as well as numerous utilities services. Nevertheless, the results highlight that significant archaeology continues to survive at a relatively shallow depth, enabling us to trace historic land use and landscape change within this part of the city across many centuries.

Section drawing of one of the watching brief trenches, showing a medieval wall surviving at less than one metre below the current ground surface, amidst much modern disturbance.
Section drawing of one of the watching brief trenches, showing a medieval wall surviving at less than one metre below the current ground surface, amidst much modern disturbance

Andrew Pearson
Post-excavation Manager

Share this!