Shortly after the year 1000, the bishops of Poitiers from the Isembert family, succeeding a family named Chauvigny, became lords of Chauvigny, and later barons from the 14th century onward. The baronial castle, also known as the Bishops’ Castle, was built in the 11th century by them. The quadrangular keep dates from the mid-11th century. Starting in 1397, Ithier de Mareuil, bishop of Poitiers from 1394 to 1405, added a second keep to the castle. Today, it hosts falconry shows.
The structure is a complex building, 80 meters long and 50 meters wide. It was frequently damaged and altered. By the late 17th century, it was already nearly abandoned.
You can still see a first enclosure with the original 11th-century entrance, a powerful 12th-century keep, the ruins of the 'new castle' built around 1400 (of which an impressive wall section remains, showing two stories of apartments) and the Saint-Michel chapel with its chapter room above. Access to the inner courtyards and buildings of the second enclosure (12th–16th centuries), including kitchens, bakeries, stables, a well, and a tunnel, was via a drawbridge. The castle chapel can be recognized by its vaulted ceiling bearing the coat of arms of Ithier de Mareuil.
The castle's current ruined state is due to its sale as national property during the French Revolution, after which the buyer turned the fortress into a stone quarry.
Rosenborg Palace was built in the period 1606-34 as Christian IV’s summerhouse just outside the ramparts of Copenhagen. Christian IV was very fond of the palace and often stayed at the castle when he resided in Copenhagen, and it was here that he died in 1648. After his death, the palace passed to his son King Frederik III, who together with his queen, Sophie Amalie, carried out several types of modernisation.
The last king who used the place as a residence was Frederik IV, and around 1720, Rosenborg was abandoned in favor of Frederiksborg Palace.Through the 1700s, considerable art treasures were collected at Rosenborg Castle, among other things items from the estates of deceased royalty and from Christiansborg after the fire there in 1794.
Soon the idea of a museum arose, and that was realised in 1833, which is The Royal Danish Collection’s official year of establishment.