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 prosperity of Dunster was based on the wool trade, with profits helping to pay for the construction of the tower of the Priory Church of St George and provide other amenities. The 15th century Gallox Bridge was one of the main routes over the River Avill on the southern outskirts. The market was held in "The Shambles" however these shops were demolished in 1825 and now only the Yarn Market remains. Dunster Beach, which includes the mouth of the River Avill, is located half a mile from the village, and used to have a significant harbour, known as Dunster Haven,