This entry is rather a fraud. No physical evidence of the castle remains. Its existence and site are known from documentary sources and a dig to the rear of the Old Bell found large stone blocks but the exact location is a mystery. Even this illustration is a fraud as it is of Devizes castle as an archaeologist thought it might have been; the connection is that both castles were built by Bishop Roger of Salisbury as part of a strategic system to impose authority over a lawless land. Malmesbury Castle played a significant role in the “anarchy”, the civil war between Stephen and Matilda. It was held by King Stephen in the midst of a countryside which favoured Matilda and it was besieged three times but was never taken. The last occasion was in1135 towards the end of the war; shortly afterwards a peace was negotiated. Stephen would remain King but when he died Henry, Matilda’s son, would receive the crown.
Presumably once the war ended the monks would have felt secure enough to start building the Abbey we see now. Constraints of space meant the west end of the building was very close to the castle and this the monks didn’t like. They petitioned the king and some time later in 1216 King John sold them the castle, which they promptly demolished. Doubtless it provided very useful stone for the Abbey which we think was still under construction. Rome was not built in a day nor were mediaeval abbies!