In 1383, the Davensberg branch of the noble lords of Büren acquired a newly constructed castle from Archbishop Friedrich of Cologne as a fief. It was intended as an outpost in the Almetal and was to be jointly owned by the Davensberg and Cologne Archbishop.
In 1394, the Davensbergs pawned the castle to Johann von Scharfenberg, a branch of the Padberg family. Concurrently, the noble lords of Büren pawned their half of the castle and town of Alme to Hermann von Padberg. The redemption of the Ringelstein castle took place in 1399 by Berthold von Büren.
While often suggested to defend against the Padbergs, there is no evidence linking the pawning and redemption of Ringelstein and Alme castles for this purpose.
In 1458, the castle was granted as a fief to the Landgrave of Hesse. During the Thirty Years' War, Ringelstein became a venue for witch trials, with a judicial site and torture facilities. In 1631, 55 people were convicted and executed as witches within 30 days. After 1802, Ringelstein declined in significance and fell into ruin.
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.