William de Mohun of Dunster, 1st Earl of Somerset William de Mohun of Dunster, 1st Earl of Somerset William de Mohun of Dunster, Earl of Somerset (c. 1090 – c. 1155), 2nd feudal baron of Dunster, was a favourite of Empress Matilda and a loyal supporter of her in the war against King Stephen, during which he earned the epithet of the "Scourge of the West". William was the son of William de Moion, who was seigneur of Moyon which is close to Saint-Lô. The elder William was High Sheriff of Somerset in 1084. During the war between Matilda and Stephen, Stephen marched against Mohun's castle at Dunster, but
Dunster mentioned in the Domesday Book of 1086. From that time it was the "caput" of the Feudal barony of Dunster. The Castle was remodelled on several occasions by the Luttrell family who were lords of the manor from the 14th to 20th centuries. The benedictine Dunster Priory was established in about 1100. The Priory Church of St George, dovecote and tithe barn are all relics from the Priory. The village became a centre for wool and cloth production and trade, of which the Yarn Market, built by George Luttrell (d.1629), is a relic. There existed formerly a harbour, known as