[1] The castle was named Mons Acutus - literally, sharp hill - built on land within the Saxon settlement of Bishopston that Robert had acquired from Athelney Abbey in exchange for the manor of Purse Caundle, an expensive exchange for Robert.

The castle is strategically placed to overlook and control traffic on the Fosseway Roman road and the Somerset levels, so hampering any military movements, The location for the castle is also thought to have been a deliberate political statement by Robert: before the battle of Hastings, the Anglo-Saxons had discovered what they believed to be a holy cross on the hill.

[6] The castle was unsuccessfully besieged in 1068 during a major Anglo-Saxon revolt against Norman rule, but the rebels were defeated by Geoffrey de Montbray, the Bishop of Coutances.

[7] In 1102, however, William of Mortain (Robert's son) gave the castle and the surrounding lands to the Cluniac order, who founded Montacute Priory there.

[9] The antiquarian John Leland described the castle in 1540 as "party fell to ruin", and by this period it was being quarried for its stone, ultimately resulting in its disappearance.