Cirencester Abbey

.]] Henry I transformed the church into an Augustinian abbey. Administrative records show that Serlo became the first abbot in 1130, a canon of Salisbury Cathedral who had probably served before as dean of Salisbury. The first regular canons came from Merton Priory. The new foundation absorbed the older church's revenues and undertook a major building campaign for church and claustral ranges. The abbey church was dedicated on 17 October 1176 by Bartholomew of Exeter.

Cirencester's cloister lay on the north of the church: an unusual English arrangement that reflected the need to retain continuity with the pre-Conquest precinct. Between the 1220s and 1240s, the canons built a conduit to bring spring water to the lavatorium and refectory; by mid-century there is clear evidence for piped water serving claustral and domestic ranges, and for management of watercourses at Spital Gate and within the precinct. The precinct was large, bounded by the River Churn and crossed by the Gunstool Brook; gates included the surviving Spital Gate (also known as the Almery or Abbey Gateway).

A secular college serving a large minster parish existed by 1086; its endowment was later swollen by estates of the royal clerk Regenbald. Medieval and later assertions that Regenbald was 'dean' or that a full prebendal structure existed before the abbey are the fruit of later misunderstanding and documentary tampering. According to Florence of Worcester, Henry I began a 'new work' at Cirencester in 1117, which has often been assumed to mark the beginning of the abbey's construction, but it is impossible to link this statement definitively to the abbey.