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
Dunster Castle with a supply of venison as well as generating income. During the 15th century, England was divided by the prolonged period of civil war called the Wars of the Roses: the Luttrells were supporters of the House of Lancaster. In 1461, Sir James Luttrell died following the Lancastrian defeat at the Second Battle of St Albans, and his family were deprived of their estates by the Yorkist Edward IV. The castle was given to the Herberts, but the Luttrells regained it on the accession of the Lancastarian Henry VII in 1485, when Dunster was restored to James' son, Sir Hugh