The castrum in Castiglione delle Stiviere was founded probably in the 9th century, but it is much altered and restored, especially by the Gonzaga family of Mantua in the 16th century. The castle was home to a cadet branch of the House of Gonzaga, headed by the Marquis of Castiglione. Saint Aloysius Gonzaga (1568–1591) was born there as heir to the marquisate, but became a Jesuit. He died tending plague victims in Rome and was buried there, but his head was later translated to the basilica in Castiglione which bears his name.
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.