Feudal barony of Dunster King Henry VII (1485–1509), he obtained the reward from that king of a reversal of his father's attainder and received restoration of his lands from the Herberts, who had never lived at Dunster, having been long seated in Wales. He was instrumental in quelling the rebellion in Devon. In 1487 on the coronation of the queen he was appointed K.B.. He was Sheriff of Somerset and Dorset in 1488. He erected the surviving sculpted stone heraldic panel above the western arch of the Gatehouse to Dunster Castle, showing on six shields (a further two blank) the arms of Luttrell, Beaumont,
Dunster Castle during the early 12th century, probably forming a shell keep around the top of the motte. In the late 1130s England began to descend into a period of civil war known as the Anarchy, during which the supporters of King Stephen fought with those of the Empress Matilda for control of the kingdom. William de Mohun's eldest son, also called William, was a noted supporter of Matilda, and Dunster was considered one of her faction's strongest castles in the south-west. In 1138 forces loyal to Stephen besieged the castle; a siege castle was built nearby, but all trace of it