Conrad I, Count of Vintimiglia, built the castle in Roquebrune-Cap-Martin in 970 to defend the Western border of his feudal domain from attack by hordes of Saracens that rampaged around the area. Initially the entire village was encompassed by the castle. The keep's military strength was reinforced in the 15th century by the Grimaldi family. In 1808 the castle was sold as a Bien National to five Roquebrune inhabitants. A century later, in 1911, it was sold again – this time to wealthy Englishman Sir William Ingram, who set about renovating it but eventually gave it to the town of Roquebrune in 1921. The castle overlooks the medieval village and its atmospheric alleyways, sometimes carved out of the rock itself.
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.