Dunster Castle the north; a third force, under the command of William de Mohun, landed by sea along the Somerset coast. William had been granted 68 manors in the region and by 1086 had established a castle at Dunster; this would form both the "caput", or principal castle, for his new lands, and help guard the coast against the threat of any fresh sea-borne attack, as well as controlling the coastal road running from Somerset to Gloucestershire. This first castle was a motte and bailey design, built upon the former Anglo-Saxon "burgh"; the top of the Tor was scarped to form the
Yarn Market, Dunster on the motte by the start of the 12th century, and the castle survived a siege during the early years of the Anarchy. At the end of the 14th century the de Mohuns sold the castle to the Luttrell family. Dunster had become a centre for woollen and clothing production by the 13th century, with the market dating back to at least 1222, and a particular kind of kersey or broadcloth became known as 'Dunsters'. The prosperity of Dunster was based on the wool trade, with profits helping to pay for the construction of the tower of the Priory Church