The Priory of Bradenstoke which is dedicated to St Mary is situated near the village of Bradenstoke-cum-Clack in the parish of Lyneham. It is placed on a high ridge of land which overlooks the Avon valley, with an abundance of local springs and a holy well close by.
There is evidence that a 17th century chapel had once occupied the site. This may have been incorporated into the priory church and could account for the narrowness of the nave and also for the fact that the church was on the south of the cloister although the site was a north-south one.
The priory's founder was Walter 'le Eurus', son of Edward of Salisbury and also father of Patrick, first Earl of Salisbury. He gave the vill of Bradenstoke and the church ( Lyneham) with all their appurtenances to found a convent of canons regular. This was to be a daughter house to St Mary's Abbey at Cirencester. This charter was confirmed before June 1139 by his wife ,Sybil, and his sons, William and Patrick, before Roger, the Bishop of Salisbury.
The early Angevin kings showed special favours towards Bradenstoke and several charters were passed by them confirming the spiritual and temporal endowments of Bradenstoke, its property and special privileges. The property of the priory grew substantially and it became very wealthy. Its chief spiritual and temporal properties were situated in Wiltshire but there were others of great value in Oxfordshire, Gloucestershire and Dorset.