Dunster Castle evidence of a fortification at Dunster was an Anglo-Saxon "burgh". This was built on the summit of the hill and was possibly intended to protect the region against sea-borne raiders; by the mid-11th century it was controlled by a local nobleman called Aelfric. In 1066 the Normans invaded south-east England, defeating the English forces at the battle of Hastings: in the aftermath of the victory, William the Conqueror entrusted the conquest of the south-west of England to his half-brother Robert of Mortain. Expecting stiff resistance, Robert marched west into Somerset, supported by forces under Walter of Douai, who entered from
Dunster Castle and Colonel Robert Blake led a Parliamentary force against Dunster in October. In November Blake began his siege of the castle, setting up his artillery in Dunster village and starting to dig tunnels to plant mines beneath the walls. The castle was briefly relieved by reinforcements in February 1646, but the siege was resumed and by April the Royalists situation was untenable – an honourable surrender was negotiated and a Parliamentary garrison installed. After the end of the Second English Civil War in 1649, however, Parliament decided to deliberately destroy, or slight, the defences of castles in key Royalist areas,