The castle complex on the Willibaldsberg was begun in 1355 and extended in the second half of the 16th century under Martin von Schaumberg. It was transformed into an impressive residence by Elias Holl during the reign of Prince-Bishop Johann Conrad von Gemmingen (1595-1612) – at this stage of the building's history the towers were crowned by onion domes.
Gemmingen also laid out the renowned botanical garden Hortus Eystettensis. Based on the copperplate engravings illustrating the plant collection which were created in 1613 by Basilius Besler, the Bastion Garden opened in 1998 reproduces the plant world of the original botanical garden.
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.