The date the first church was founded has traditionally been put at 716-17; the historical record does show two foundations at this date, but these were actually at Yate and Bredon. Nevertheless, a church did exist by the end of the 8th century, as King Offa founded a minster on the site between 793 and 796. The minster became a Benedictine priory around 963-64. It was the first reformation of a minster by Bishop Oswald of Worcester, in his introduction of the Rule of Saint Benedict into the diocese. He brought the English monk Germanus from Fleury Abbey as the new Prior. However Oswald soon decided to move the community to Ramsey, after he acquired land in 966 for the foundation of Ramsey Abbey. The priory buildings eventually fell into disrepair. Around 1093 Bishop Wulfstan reacquired the dilapidated priory and rebuilt it as a monastery under the control of the Worcester diocese.
Collegiate church
Over the next century, there were successive evictions as monks and secular priests alternated in possession of the monastery; this was finally resolved in favour of the secular priests when the church become collegiate around 1194. The canons of Westbury College were each supported by revenues from one of the areas around Westbury on Trym, including Aust, Henbury and Lawrence Weston. The great reformistJohn Wycliffe was a canon from 1362 until his death in 1384, although in 1367 he was accused of neglecting his duties as prebendary of Aust due to his long absence. The prominent Bristol merchant William Canynge was dean of the college from 1469 until his death in 1474. In 1544, with the Dissolution of the Monasteries, the church became a parish church within the new Bristol diocese, and the residential buildings of Westbury College passed into the hands of Sir Ralph Sadler.
Architecture
The present building all dates to after 1194. The nave and aisles are early 13th century, in the Early English style. The remainder of the church is in the Perpendicular style. The nave clerestory, chancel, choir and north chapel are the result of extensive rebuilding by Bishop Carpenter in the middle of the 15th century. The chancel has a polygonal apse, which is rare for the late Gothic period. The church tower, although also from this period, was restored in the middle of the 19th century. The reredos, which depicts the Last Supper, is also 19th century.
Memorials
Although Bishop Carpenter's plan to make the church a joint cathedral with Worcester did not come to fruition, it was he who rededicated the church to the Holy Trinity. On his death in 1476 he was buried in the crypt underneath the altar. The stone cadaver from his cadaver tomb is in the chancel, with a Purbeck marble canopy donated in 1853 by Oriel College, Oxford, where he had been Provost.
