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 has been lost. William successfully held the castle and was made the Earl of Somerset by the grateful Empress. Chroniclers complained of the way in which he subsequently raided and controlled the region by force during the war, causing much destruction. In the aftermath of the conflict, William's son, another William, inherited the castle after a short period of royal ownership under Henry II. William appears to have insisted that his tenants agree to help repair and maintain the castle walls as part of their feudal service. 13th to 17th centuries In the 13th century the Lower Ward was rebuilt in stone by Reynold Mohun; this was paid for in part by Reynold commuting his tenants' ongoing duty to repair the castle walls into a single, one-off financial payment to their lord, and partially through his marriage to a rich local heiress. A survey of the castle in 1266 described the Upper Ward on the top of the motte as containing a hall with a buttery, a pantry, a kitchen, a bakehouse, the chapel of Saint Stephen and a knight's hall, guarded by three towers. The Lower Ward included a granary, two towers and a gatehouse; one of the towers, called the Fleming Tower, was used as a prison. The castle stables lay outside the defences, further down the slope. By the end of the 13th century some of the castle's roofing had been covered in lead, while other parts still used wooden shingles. In 1330 Sir John de Mohun inherited the castle; John, although a notable knight, was childless and fell into considerable debt. His wife Joan took over the running of their estates, and when John died in 1376 she agreed to sell the castle to Lady Elizabeth Luttrell, the leading member of another major Norman family, for 5,000 marks, with the castle to transfer to Elizabeth on Joan's death. At some point during this period additional stone buildings were constructed along the Lower Ward, on the side of the current mansion, and records suggest that a ditch, or moat, may have existed around the base of the Tor in the 14th century. Joan outlived Elizabeth, and in