The ruins of St Oswald's Priory are only fragmentary, and are surrounded on most sides by modern development, close to Gloucester city centre, yet they are still atmospheric and evocative, on account of the aged masonry, in a variety of styles, and several well-preserved architectural features. The surviving elements are all from the priory church; most of the arcade wall between the nave and the north aisle, and an archway at the east end of this aisle, and are bordered by a tree-lined garden, after removal of several adjoining buildings that had encroached on the original site. The walls give an impression of great age, and place is peaceful, though the tranquillity is just a little spoilt by a nearby main road, the A417, here known as St Oswald's Road.
The site is owned by Gloucester City Council, and free parking is available along a minor road (Archdeacon Street) that runs along the south side.
The religious institution, initially a minster dedicated to St Peter, was founded around 900 by Ethelfleda (died 918), eldest daughter of King Alfred, and situated right beside the River Severn, long before it was diverted to its current course a little further west. The first permanent structure was a church using some stones recycled from Roman buildings, consisting of a nave, chancel, apse and crypt, this latter housing the bones of St Oswald of Northumbria, recently recovered from Danish invaders. Some of brickwork from this church is incorporated into the surviving wall, surrounded by later additions. The church was strengthened early in the 11th century, probably to facilitate addition of a tower, followed by further modifications before and after the Norman conquest, up until conversion to an Augustinian priory, in 1152. In the next hundred years various outbuildings were added including cloisters and a guest house to the south, and the church was extended westwards by two bays.
The priory was dissolved in 1536 by order of Henry VIII, after which the guest house became a private dwelling and a new church was built incorporating the north aisle and north transept of the existing church, the remainder of which was demolished or left to become ruinous. This replacement church, used by the parish of St Catherine's, was short lived since it was damaged during the Civil War, and was largely removed in 1653, leaving just the original nave wall, and this is the section surviving today. A third church, also for the parish, was erected just to the north in 1867 but this was in operation only briefly, pulled down in 1921. The guest house, the only other substantial relic from the priory, was dismantled around 1824.
The north wall of the priory church consists of six bays; the westernmost (and larger) two are from the 12th century extension. The arches in these bays are fully blocked with brickwork from the church built shortly after the Dissolution, and contain two small windows, one of two lights, the other of three. The remaining four bays all have 12th century arch frames adjoining some of the original 10th century masonry. Two are open while the others contain masonry from the 16th century church; one completely blocked, the other centred on a doorway. The transverse arch, on the north side, dates from around the Norman conquest. Hedges and paths to the south indicate the position of the (square) cloisters, the southern corner of which lies beneath Archdeacon Street.