The site was originally a monastic church built in 674 AD by St Wilfrid. From 678 to 821 AD it was a cathedral, however in 875 it was destroyed by the Vikings. It was refounded as a Priory in 1113 for Augustinian canons and dissolved in 1537.
Excavations from 1984-93 located the early monastic complex beneath the nave of the present abbey church. There was undoubtedly a second church, St Mary's, on the site, probably a little to the south-east of the main priory church, which was dedicated to St Andrew. The Anglian monastic church was aisled, the south aisle being wider than the north, as at Jarrow. The east end of the church has not been definitively located, but would not have extended much beyond the crypt. There was also a separate apsidal chapel to the east of the church and crypt, which was axially aligned with them. A little evidence for the Romanesque foundation has come to light, and tentatively shows an apsidal church with cloister to the south. It is not certain how much of the pre-Conquest structure was retained in the Romanesque church beyond the south wall of the nave. In the late 12th to early 13th century, the whole eastern end of the site was demolished and remodelled on a much enlarged scale, and the cloister was also enlarged. The church is still in use and the gatehouse and chapterhouse are incorporated in later buildings.
Various Roman altar stones and other Roman inscriptions have also been found within the church.