In the 9th century, a wooden castrum was built on a rocky promontory to fend off Viking raids near Durivum (Saint-Georges-de-Montaigu). Later, a stone keep was added with strategic upgrades, including a drawbridge. The Montaigu family, later known as Belleville, pledged loyalty to the Plantagenets. Over time, the property changed hands through marriages and alliances, including a notable period of privateering by Jeanne de Belleville. The fortifications of Château de Montaigu were enhanced in the 15th century under Louis XI's guidance to protect against Breton threats.
Some visible remnants still exist. Originally, there was an oval-shaped enclosure with about ten towers and an entrance gatehouse located in the northeast. The fortified town was situated to the north of the fortress and extended slightly to the east. A dry moat separated the fortified town from the fortress. A barbican protected the entrance gatehouse. A Romanesque keep of the Niort type, with its courtyard and a small enclosure, was located in the castle's courtyard, roughly in the middle in the north-south direction and facing west.
Inverness Castle sits on a cliff overlooking the River Ness. The red sandstone structure evident today was built in 1836 by architect William Burn. It is built on the site of an 11th-century (c. 1057) defensive structure. Today, it houses Inverness Sheriff Court.
The castle is said to have been built by Máel Coluim III of Scotland, after he had razed to the ground the castle in which Macbeth of Scotland according to much later tradition, murdered Máel Coluim"s father Donnchad I of Scotland, and which stood on a hill around 1 km to the north-east.
The first Inverness Castle was partially destroyed by King Robert I of Scotland and a replacement castle was sacked in the 15th century by the Clan Donald during the Siege of Inverness (1429). The castle was occupied during the Raid on Ross in 1491.
In 1548 another castle with tower was completed by George Gordon, 4th Earl of Huntly (1514–1562). He was constable of the castle until 1562.