Keynsham commands a strategic position on the south side of the Avon, overlooking both that river and its tributary from the Mendip Hills to the south, the Chew. It controls the road between Bristol (giving access to the Bristol Channel and beyond) and Bath (giving access to London) on its side of the river. The road now running from Keynsham to Willsbridge, west of Bitton, probably represents an important ancient route.

Keynsham Abbey was founded as a house of Augustinian canons c1166. The Abbey precinct occupied c.18 acres above the left bank of the Chew, c.200m above its confluence with the Avon. After the Dissolution, the Abbey was demolished piecemeal over 400 years. The Abbey Church lay in a garden in Abbey Park, and has been the subject of several excavations which have yielded Romanesque sculpture (Brock, 1875, Lowe et al. 1987, 2004, 2005). There is a plan of the Abbey in Lowe 2004 and on the Keynsham Abbey website. Elements of sculpture from the Abbey can be seen embedded in the late 17thc archway of Park House (formerly Keynsham House). There is a lapidary collection in Keynsham Town Hall. Other elements of sculpture are located in the Crown Inn, the former Somerdale Factory site and Bristol Road arches. These sites are the subject of separate reports.

There had been a religious settlement in Keynsham during the 9thc and 10thc (Lowe, 2006), but the Abbey was founded by William, Earl of Gloucester following his son's Robert's death in 1166, and (according to tradition) at his son's dying request. It was founded as a house of Augustinian canons regular and adopted the order of Saint Victor, so that the head of the house was called an abbot, and the house was known as the House of the Canons of Saint Austin and Saint Victor.

At its foundation the whole of the manor and hundred of Keynsham, an area of 24, 520 acres was conferred on the Abbey. In 1276, Edward I stayed at the abbey on his way from Bath to Bristol. A township eventually grew up around the Abbey, and in 1307 Edward II granted the abbey a weekly market and a yearly fair on the festival of the assumption. These rights were confirmed by Edward IV in 1461. The abbey also acquired considerable property in Ireland. At the Dissolution the Abbey was surrendered to the King in 1539. (Page, 1911).