The lordship of Sigournais has existed since at least 1050. It was then the property of Zacharie de Pouzauges, a vassal of the vicomtes de Thouars. In the 12th century, a priory dedicated to Saint-Saturnin was built within the walls of the castellum. Issues of cohabitation with the castle's inhabitants arose. Moreover, the current castle, built by Guyard de Sainte-Flayve, came into existence thanks to the relocation of the priory outside the enclosure.
Nothing remains visible from the ancient fortress of the 12th century; the foundations in the ground are located a bit further to the north, with the current castle covering a part of them.
The current castle, constructed under Guyard de Sainte-Flayve, dates from the late 15th century and has an almost pentagonal shape. This enclosure consists of curtain walls flanked by eight round towers and a large gatehouse tower. A dry moat carved into the limestone surrounds it all. The gatehouse tower serves as both a fortified entrance (gatehouse) and a main tower (keep). It consists of a large rectangular tower flanked by two round towers on each side, all crowned with a battlemented walkway on machicolations. The entrance corridor is divided into two entrances, one for carts and one for pedestrians. On the outside, a fixed bridge was extended by a cart bridge and a pedestrian drawbridge, side by side. Inside the gatehouse tower, there were two levels. On the first level, there was a guard room and a vestibule. Canon openings were arranged in the thickness of the wall. On the second level, accessible by the spiral staircase in the South flanking tower, there was a room serving both as a reception hall and as the lord's residence, separated by a wall was a chamber.
A large pentagonal courtyard was protected by walls and towers, crowned with crenellated battlements on machicolations, and probably served as a bailey (outer courtyard). Some buildings were attached to the ramparts, such as stables, kitchens, a bakery, forge, etc.
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.