Erlach Castle was built around 1090-1100 by Burkart von Fenis, the Bishop of Basel. In 1224, the castle and town of Erlach became the property of the Counts of Nidau. In 1265, Peter II of Savoy brought the counts and their castle under the feudal authority of the House of Savoy. While under Savoy control, Peter II appointed a warden to occupy the castle and manage the castle estates. The warden knights took their name from the castle and town and became known as the von Erlach family. The von Erlach family would later produce a number of famous leaders, including Rudolf von Erlach, the victorious Swiss commander during the Battle of Laupen. By 1300 the von Erlachs were citizens of the city of Bern. After the death of Isabella of Neuchatel, the widow of the last Count of Nidau, in 1395 Erlach was managed directly by the House of Savoy. They mortgaged the town to the de Chalon family in 1407.
In 1474 it was conquered by Bernese troops during the Burgundian Wars and remained under the control of the city of Bern. The first governor of the newly captured district was Rudolf von Erlach, who had been the castellan under the de Chalon family.
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.