Dunster Castle motte, or Upper Ward, and an area below shaped to form the bailey, or Lower Ward. Somerset became more stable in the aftermath of the post-invasion period and the unsuccessful 1068 rebellion against Norman rule. It was common in the period for the Normans to build religious houses to accompany major castles, and accordingly William de Mohun endowed a Benedictine priory at Dunster in 1090, along with its parent abbey at Bath. The River Avill was important for trade; the region around Dunster was rich with fisheries and vineyards, and Dunster Castle prospered. Stone fortifications were built on the site
Dunster Castle the Commonwealth years and the Restoration of Charles II to power in 1660. Francis' heir, another Francis, married a wealthy heiress worth £2,500 a year (£331,000 in 2009 values) and with this income set about modernising the castle during the 1680s, in particular building a grand staircase in the latest style. Francis was a colonel in the local militia and in 1688 backed William of Orange's attempt to oust James II; when William landed in Devon, Francis mustered a number of companies of infantry at Dunster on 19 November to support him, which formed the basis for the later Green