The original castle on the Marienberg, a hill which was first settled in the late Bronze Age, was probably a small fort built early in the 8th century by the Franconian-Thuringian dukes, together with a church which in 741 became the first church of the Würzburg bishops. From 1200 an unusually large castle was built, which was extended during the late Middle Ages and the Renaissance.
Following the storming of the castle in 1631 by the Swedes, Prince-Bishop Johann Philipp von Schönborn built a circle of massive bastions to protect the Marienberg. In 1945 the fortress was almost completely burned out, and its reconstruction was only completed in 1990.
On the first floor of the Princes' Building Museum (administered by the Bavarian Palace Department), is the Bibra Apartment with valuable furniture, tapestries and paintings, the Princes' Hall with early Gothic arcatures and the large Echtersche family tapestry, as well as a treasury and vestment chamber from the era of the prince-bishops. On the second floor is the Main-Franconian Museum documenting the history of the fortress and town.
The 1,300 m2 Princes' Garden is accessible from the castle courtyard: it was reconstructed in 1937-38 on the basis of plans dating from the early 18th century.
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.