The ancient name of Pietra Ligure was La Pietra , and referred to the imposing calcareous rock that is found to the east of the historical center, above which the Roman castrum was built. The castle, enlarged in the period of the barbarian and Saracen invasions (6th-9th century), was a bishop ‘s property and reached its present size in the 16th century. It is believed that this natural barrier, easily defensible, constituted a border point between the Byzantines and the Lombards .
The Byzantine castrum was probably destroyed by King Rotari, but in the same site the medieval castle, stronghold of the bishops of Albenga, was built in the 12th century , subject then to frequent attacks by the Del Carrettos of Finale . To the west of the castle a hamlet developed, surrounded by turreted walls and endowed with five gates: the port of the marina protected by a bastion to the south, the gate of Santa Caterina near the homonymous rural oratory to the north, the door of the porch protected by the tower of via Rocca Crovara and the royal gate to the west, the door to the slaughterhouse to the east. After various vicissitudes, the village was definitively ceded by Pope Urban VI to Genoa , in 1385 , and acquired considerable importance as an advanced point of the Republic between the Finale and Loano , fiefdom of the Doria .
The castle remained the property of the bishops of Albenga, who sold it to the Arnaldo at the end of the fourteenth century . It then passed into the possession of other patrician families and was enlarged in 1550 with the addition of a wing facing south-west, an arch in the eastern part in addition to the two sentry boxes. Due to the Saracen raids the upper square was armed with two large cannons, which were sent back to Genoa at the end of the 18th century in view of the French invasion. The medieval part, at the end of the fifties of the twentieth century , has been restored and transformed into a meeting place. The solid masonry resting directly on the rock, the impervious position, the vaulted passages and the low rooms of the dungeons known as “Grimaldina”, due to the fact that two Grimaldi brothers from Monaco were imprisoned there at the end of the fourteenth century, justify the importance of the castle exercised in the local defense system.References:
The Château d'Olhain is probably the most famous castle of the Artois region. It is located in the middle of a lake which reflects its picturesque towers and curtain walls. It was also a major stronghold for the Artois in medieval times and testimony to the power of the Olhain family, first mentioned from the 12th century.
The existence of the castle was known early in the 13th century, but the present construction is largely the work of Jean de Nielles, who married Marie d’Olhain at the end of the 15th century.
The marriage of Alix Nielles to Jean de Berghes, Grand Veneur de France (master of hounds) to the King, meant the castle passed to this family, who kept it for more than 450 years. Once confiscated by Charles Quint, it suffered during the wars that ravaged the Artois. Besieged in 1641 by the French, it was partly demolished by the Spaniards in 1654, and finally blown-up and taken by the Dutch in 1710. Restored in 1830, it was abandoned after 1870, and sold by the last Prince of Berghes in 1900. There is also evidence that one of the castles occupants was related to Charles de Batz-Castelmore d'Artagnan, the person Alexandre Dumas based his Three Musketeers charictor d'Artagnan on.
During the World War I and World War II, the castle was requisitioned first by French troops, then Canadian and British soldiers. The current owner has restored the castle to its former glory.