Loučeň Castle was built on the site of a former medieval fortress. The first mention of this fortress dates back to 1223 and was discovered in the testimonial of the Prague bishop Peregrinus. This year is also considered the first official mention of the village of Loučeň. From that time until 1618, several lords and peasants alternated as owners of the fortress.
In 1612, the castle of Loučeň and other adjacent villages were owned by Václav Berka of Dubá the Elder, a very wealthy nobleman who did not sympathize with Emperor Ferdinand II. Therefore, in 1620, after the Battle of White Mountain, Václav Berka left the country and the castle was confiscated in 1622 due to his participation in the anti-Habsburg uprising. A year later, all of Berka's property was purchased by Adam of Valdštejn.
During the Thirty Years' War, all the surrounding villages in the Nymburk region were heavily affected by the invasion of armies. The dilapidated fortress in Loučeň was not renovated until 1704-1713, when Karel Arnošt of Valdštejn began to transform it into a Baroque castle. A chapel was also added to the castle, which was later converted into the Church of the Assumption of the Virgin Mary. After Karel Arnošt's death, his daughter Eleanora took over the estate, and she passed it on to her daughter Maria Anna. She was very determined, persecuted evangelicals, and tightened the requirements of serfdom. Maria Anna married Josef Fürstenberg, and thus the ownership of Loučeň Castle passed from the Valdštejn family to the Fürstenbergs.
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.