Feudal barony of Dunster of Dunster, was as follows: William de Moyon (died post 1090) ("alias" de Moion, later de Mohun), Domesday Book holder of Dunster Castle, 1st feudal baron of Dunster, was Seigneur of Moyon near Saint-Lô in Normandy and was Sheriff of Somerset in 1086. He was the founder of the English "de Mohun" family, prominent in the Westcountry, extinct in the male line seated at Dunster in 1375 and extinct in the junior male line seated at Mohuns Ottery in Devon at about the same time. He is recorded in the Domesday Book of 1086 as holding the manor of "Torre"
Dunster Castle designated by English Heritage as a Grade I listed building and Scheduled Ancient Monument. The castle has required continuing maintenance work, in particular to its roof, itself an important historical feature. Efforts have been made to gradually redecorate the castle in a period style, using reproductions of original wallpapers and materials. The National Trust installed solar panels behind the battlements on the roof in 2008 to provide electricity and make the premises more environmentally friendly. This was the first time the National Trust have taken this approach to a Grade I listed building, and it is expected to save 1,714