Château de Châteaubriant is first mentioned between 1030 and 1042. It was first built by Brient, an envoy of the count of Rennes, to create an outpost in the Pays de la Mée. The first castle was a motte-and-bailey structure made of wood. It dominated the river Chère and the Rollard and had two concentric moats. One was dry, the other filled with water. It also had a big square keep, rebuilt in stone around 1100. Two halls and a chapel were added during the 12th century, the latter being completed in the 13th century. In the same period, Châteaubriant emerged as a town on the banks of the Rollard. City walls were built between the 13th and the 15th centuries. The upper-ward gatehouse, the curtain wall and most of the towers were built during the 13th century. The gatehouse still includes its two towers which were originally 25 meters high. The halls and the keep were rebuilt in the 14th century, and the lower-bailey gatehouse was completed before 1400.
During the war between Brittany and France, Breton castles were taken one after the other by the French. Châteaubriant was besieged in 1488 and surrendered after one week. At the end of the war, Françoise de Dinan had the castle restored and improved. As the old walls did not fit the new military exigences, a bastion was built. The keep and the halls, which also lost their defensive capacity, were opened by large windows. Inside, the baroness ordered new fireplaces in the Flamboyant style.
The improvements on the keep and the halls were not sufficient for Françoise de Dinan who wanted a fashionable residence. She ordered a new palace, built in the lower bailey. This palace has been called Bâtiment des Gardes ('guards' building') since the French Revolution, because it was then used by the National Guard. The new residence was completed at the beginning of the 16th century, after the death of Françoise. At that time, Châteaubriant belonged to Jean de Laval, her grandson and a member of the House of Laval.
However, Jean de Laval was not satisfied with the new palace, a stark building typical of the First Renaissance. He ordered a new wing, built around 1530 in an Italian style, and characteristic of the Second Renaissance. Jean de Laval is also responsible for the long gallery which forms an angle with the palace.
Châteaubriant belonged to the House of Montmorency until 1632 when Henri II de Montmorency was dispossessed and beheaded for felony. The barony was given to the Princes of Condé who kept it until the French Revolution. During the Revolution in 1789 the National Guard of the town settled in the château, which was also used to house various storehouses and a police station.
The castle was acquired by Duke of Aumale in 1845. The Duke settled in the house built by the mayor Martin Connesson and refurbished it. Being a son of Louis-Philippe I, he followed his father to England after the Revolution of 1848 and sold the château to the Loire-Atlantique département in 1853. The sous-préfecture moved there in 1854, and the 1822 house became the residence of the sous-préfet. The police station, the court and the jail, which were relocated somewhere else after the Duke of Aumale acquired the estate, came back in 1855.
In 1944, the southern end of the Renaissance palace was destroyed during an American bombing raid. Major restoration campaigns were carried out in the 1960s and after 2000. Nonetheless, the château has never been fully opened to visitors, who can only access the wards and some rooms, such as the Chambre dorée and the Bâtiment des Gardes which hosts exhibitions.
The castle is divided between an upper ward and a lower bailey. The bailey, on the south, is opened by a 14th-century gatehouse, the Pavillon des Champs, which is the main entrance for the whole castle. The upper ward is accessible from the bailey through a second gatehouse. It is located on the highest point, dominating the Chère, and it is bordered by the seigniorial buildings: the two halls and the chapel.
The keep is built on both the upper and lower ward and also dominates the Chère. It was built in stone around 1100 on the site of the primitive motte. Later rebuilt in the 14th century, it felt into ruins during the 18th century. Remains of machicolation are visible on the top. The two halls form an angle with the keep. They were rebuilt in the 14th century and the opening of new windows after the Mad War did not alter their austere look. The small hall, partially destroyed, has a peculiar roof, similar to a flat onion dome, made around 1562. The result is somewhat clumsy and is only an experimental attempt.
Located close to the small hall, the chapel was built around 1142 and refurbished in the 13th century. Some hundred years later, it was divided in two and the western part was turned into the chaplain's house. The monument is romanesque but gothic windows were added in the 16th century. The windows on the chaplain's house form a single bay culminating with a gothic dormer. Mural paintings and 15th-century floor tiles were discovered during archeological excavations.
The Bâtiment des Gardes is the oldest Renaissance building and also the less decorated. It was built around 1500. Its slate roof is steep and as tall as the facade itself, which gives a massive look to the whole. The facade is opened by large regularly positioned windows on the first floor and small irregular doors and windows on the ground floor. The facade on the moat is framed by two medieval towers which were opened by new large windows.References:
Frösöstenen is the northern-most raised runestone in the world and Jämtland's only runestone. It originally stood at the tip of ferry terminal on the sound between the island of Frösön and Östersund. The stone dates to between 1030 and 1050. It has now been relocated to the lawn in front of the local county seat due to the construction of a new bridge, between 1969 and 1971, on the original site.
Frösö runestone inscription means: Austmaðr, Guðfastr's son, had this stone raised and this bridge built and Christianized Jämtland. Ásbjörn built the bridge. Trjónn and Steinn carved these runes.