The steep plateau of Saint-Blaise oppidum is accessible only from the south, therefore easy to defend, was inhabited from the Neolithic until the end of the 14th century with a long interruption during the High Roman Empire (from the 1st to the beginning of the 4th century AD). The excavations undertaken by Henri Rolland in 1935 and continued after his death, have brought to light eight archaeological layers.
There are today remains of Hellenistic rampart (2nd century BC), surmounted by the early Christian walls, a Christian necropolis, and foundations of 11th century church. The Chapelle St-Blaise is a 12th century Romanesque building, restored in the 13th century and whose facade was redone in 1608.
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.