In 675 Osric, King of the Hwicce, granted the Abbess Berta 100 hides near Bath for the establishment of a convent. The religious house later changed into a monastery, under the patronage of the Bishop of Worcester.
But the powerful King Offa of Mercia successfully wrested 'that most famous monastery at Bath' from the bishop in 781. William of Malmesbury tells us that Offa rebuilt the monastic church, which was dedicated to St. Peter. It was fine enough to impress monarchs. In 957 Bath monastery was described by King Edwy as 'marvellously built'
By that time monasticism had lapsed in England. Edwy's brother Edgar began its revival on his accession in 959. He encouraged monks to adopt the Rule of St Benedict. Bath Abbey was reformed under Abbot Ælfheah (St Elphege).
On the death of William the Conqueror in 1088, Bath was ravaged in the struggle for power between his sons. The victor, William Rufus, granted the city to a royal physician, John of Tours, who became Bishop of Bath and Wells and Abbot of Bath in 1088. The aim was to move the see of Somerset from Wells - a comparatively small settlement - to the walled city of Bath.
So St Peter's was raised to cathedral status. Since the roles of bishop and abbot has been combined, the monastery from then on was run by its prior, and so became a priory.
John of Tours planned a new cathedral on a grand scale, dedicated to SS Peter and Paul. When finished it was about 330 feet (100 metres) long. Only the ambulatory was complete when he died in 1122. The half-finished cathedral was devastated by fire in 1137, but worked continued and it was completed by about 1156.
However, later bishops preferred Wells, whose canons had successfully petitioned the pope to regain cathedral status. Bath Cathedral gradually fell into disrepair.
When Oliver King, Bishop of Bath and Wells, visited Bath in 1499 he was shocked to find the church ruinous. He took a year to consider what to do about it. In October 1500 he wrote to the Prior of Bath to explain that a large amount of the priory income would be dedicated to rebuilding the cathedral. Work probably began the following spring. Bishop King planned a smaller church, covering only the area of the Norman nave. He did not live to see the result. The new cathedral was completed just a few years before the dissolution of the monasteries by Henry VIII.
In January 1539 Prior Holloway surrendered Bath Priory to the Crown. The church was stripped of lead, iron and glass and left to rot. It was rescued a generation later by the citizens of Bath. From 1572 to 1617 it was restored to serve as the grand parish church of Bath.