The New Minster of St Oswald (also known as St Oswald's Priory) was the last minster to be built in Gloucestershire. It was traditionally founded in the 7th century by a son of Penda of Mercia, but certainly refounded in 909 by Aethelflaeda and Aethelred of Mercia. They successfully brought the bones of St Oswald, the Northumbrian King and saint, from East Anglia in the raid of 909, and placed them in the minster. Aethelflaeda and Aethelred were both buried there and the minster was for a short time the major minster of the Mercian royal household. It was endowed with land from the older minster of St Peter. After Wessex took the Saxon ascendancy, the minster never regained its early pre-eminence.
The monks abandoned the priory during the Danish wars and were replaced by secular canons. The minster remained unreformed until 1153 when it was reformed to the Augustinian Order. The monastery was under the See of York and never prosperous, and was suppressed in 1536.
After the Dissolution, the priory church became the parish church of St Catherine, but this was destroyed in the siege of 1643. The sole remains are parts of the North arcade and adjoining West wall of the North transept.
Excavation has recovered the plan of the Saxon church. It was cruciform, but unusually had an apsidal West end, very much a continental fashion of the early 10th century.