Of the rectangular buildings with free-standing keep, built in the 12th century, only the remains of the east and south wings of what used to be an important castle are preserved. The alterations carried out in the 18th century, following diverse war damage, resulted in the palatial building as it can be seen today. During the Second World War the castle was seriously damaged, but was reconstructed in 1952. This construction work was carried out in a simple reduced form; only on the valley side does the castle resemble its former image. Schleiden castle today is merely the remains of what used to be a much more extensive castle complex of several buildings.
References: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.