Interest: The oldest mention of Mayenne dates back to around 778, when Charlemagne restored to the bishop of Mans a villa of that name. In the 9th century, the Maine suffered attacks from the Bretons, especially between 840 and 870. The construction of the Palace of Mayenne accompanies the takeover of the border area under Charles le Chauve. It is attributed, presumably to the first Counts of Maine, allied by family to the Carolingian dynasty. Around 920, the wooden building was replaced by a stone building consisting of: . a rectangular two-storey body, whose upper room, well lit by a suite of windows, was to be intended for receptions; . a square tower, perhaps serving as a dwelling; . a staircase turret leaning against the tower; . terraces with access to three sides of the building. Shortly afterwards, a stone enclosure succeeded the rampart. In the 11th century, Maine was no longer threatened by Brittany but by Anjou and Normandy. Geoffroi de Mayenne (v. 1030 - 1098), who kept the castle for the Counts of Maine, took advantage of a weakening of the Counts of Maine to appropriate it, around 1040. He participated in the seigneurial struggles, especially against William of Normandy when he seized Maine. On this occasion, the castle was set on fire in 1063. One of the major changes of this period is the addition of a floor to the Carolingian building in the 12th century. At the same time, the lower levels, including the lower room, are filled. While the distribution of Carolingian spaces remains unchanged as a whole, some changes in openings are made. In this way, granite doors are inserted into the square tower, one of which gives access to the Carolingian room, the other towards the upper courtyard. At the same time, a residential building was joined to the rampart of the upper courtyard. Today there are only two geminied bays and a chimney, visible in the courtine wall. In the fight against the Plantagenet Empire, which extends from England to Aquitaine, Philippe Auguste joined Maine in 1206. Juhel II of Mayenne, who took the king's side, strengthened his power, but his death in 1220 marked the extinction of the Mayenne lineage. The new lords, inheriting the castle by marriage, reside there less and less often. During the 13th century, the castle underwent important transformations which made it a powerful fortress, adopting the defensive principles of the Philippe-Auguste era. The main novelty is the creation of a large lower courtyard, which is five times the area of the whole. The upper court itself is equipped with towers and an entrance chestnut. The changes also concern the primitive home. Its defensive capacity increases by building a cylindrical tower at the northeast corner. At the same time, its interior appearance is ennobled by the construction of vaults, which requires a reorganization of the openings, and by the realization of a painted decor. Owned by the Dukes of Anjou since 1360, the castle of Mayenne is no longer an aristocratic residence at the end of the Middle Ages, but a garrison. As such, he participated in the events of the Hundred Years War (1337 - 1453). He was first occupied by the English from 1361 to 1364. Maine was invaded after the French defeat of Azincourt (1415). Mayenne Castle, taken in 1425 and occupied by John Falstaf, remained in the hands of the English until 1448. During this period the residential function of the castle is almost anecdotal. It serves primarily as a garrison. New buildings, forge, vaulted cellar, are erected in the high courtyard to meet new needs. Following the last occupation, architectural modifications are made to ensure a better defence of the site. An imposing tower that can carry guns and resist fire, as well as an artillery terrace are built to strengthen the castle. Mâchicoulis and cannon guns are added on two towers and on the river side walls. The castle knows its last military uses during the wars of Religion. He then belonged to Charles de Lorraine, leader of the League after the assassination of the Duke of Guise (1588). The Royal Army finally took control of it in 1592. It follows a regression of its residential and defensive characters: destruction of the buildings of the high court and arasement of the towers after 1695. The lower courtyard is transformed into a park. The first sure mention of the transformation of the castle into a prison dates back to 1674. The Mayenne General Council acquired the castle in 1824. Several arrangements are being made to accommodate ever more prisoners. In 1826 the main building was enlarged southward. Other transformations follow: - modification of openings; - construction of a wall to separate the courtyard from that of women; - total modification of the roof... Plans from 1837-1838 provide information on the layout of the castle and the upper courtyard. The castle served as a prison until 1936. Property of the municipality since 1936, the castle knows various uses until the discovery of the Carolingian remains in 1993. Today, the building presents within the upper courtyard the museum of the castle of Mayenne. The lower courtyard has been completely revised to offer a pleasant place for walking and discovery to the mayennais and tourists.