This is a list of castles in the ceremonial county of Somerset, England. The first castles - private fortified residences of a lord or noble - were built in Somerset following the Norman Conquest of England, although earlier fortified structures, such as burhs or hill forts, of which there are many in Somerset were sometimes historically described as castles. In the aftermath of his victory at the Battle of Hastings in 1066, William the Conqueror entrusted the conquest of the south-west of England to his half-brother Robert of Mortain. Anticipating stiff resistance, Robert marched west into Somerset, supported by forces under Walter of Douai, who entered from the north; a third force, under the command of William de Moyon, probably landed by sea along the Somerset coast. These lords defend