Dunster Castle motte, or Upper Ward, and an area below shaped to form the bailey, or Lower Ward. Somerset became more stable in the aftermath of the post-invasion period and the unsuccessful 1068 rebellion against Norman rule. It was common in the period for the Normans to build religious houses to accompany major castles, and accordingly William de Mohun endowed a Benedictine priory at Dunster in 1090, along with its parent abbey at Bath. The River Avill was important for trade; the region around Dunster was rich with fisheries and vineyards, and Dunster Castle prospered. Stone fortifications were built on the site
Gallox Bridge, Dunster to pay for the construction of the tower of the Priory Church of St George and provide other amenities. The name Gallox is believed to be derived from gallows as the village gallows were nearby, when it was called Gallocksbrigge. The bridge is close to Dunster Working Watermill and the base of the hill on which Dunster Castle sits and provides access to the site of the Deer park. It also falls within the Dunster Conservation Area. It has been in the guardianship of English Heritage since the 1950s. It is a narrow stone packhorse bridge, on the southern outskirts