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 left in the castle grounds, the remaining servants had little to do. John's brother Henry inherited in 1857, but he too lived in London rather than at Dunster. George Luttrell inherited the castle in 1867 and began an extensive modernisation, backed by the considerable income from the Dunster estates – in a period of agricultural boom in England, the estates were producing £22,000 in revenue a year (£1.49 million at 2010 prices). It was fashionable during the mid-Victorian period to remodel existing castles to produce what was felt to be a more consistent Gothic or sometimes Picturesque appearance and George,