The earth and timber stronghold Gerdauen was constructed by the Teutonic Knights in 1270. After a subsequent Prussian uprising, the Knights were too weak to keep hold of all their fortresses. Gerdauen was burnt down, but once the Prussian uprising was put down, the Teutonic Knights returned here and began to raise new fortifications. By 1310, a new stronghold had been completed. At that time it was guarded by embankments, moats and shelters. Inside the ring of fortifications, stone and brick buildings for a convent of Teutonic brothers were constructed.
Initially the Knights planned that Gerdauen would become a seat of a commander, known as komtur. But this idea was soon relinquished because of the proximity to the Lithuanian lands and frequent attacks staged by Lithuanian troops. Gerdauen for example was attacked in 1336, 1337 and in 1366.
Although in 1406 Gerdauen Castle was surrounded by a ring of fortified walls less than half a century later, in 1455, which was during the Thirteen Years' War, the fortress was severely damaged. In 1670 it stood empty. Soon afterwards it was sold to a private owner. All that had remained of the original buildings were the cellars.
In 1872 a new beautiful palace was raised on this location. Gerdauen flourished until 1814, that is until the outbreak of World War One. In that year, the town was a witness and a victim of a bloody fight with the Russian army. Gerdauen was not rebuilt until 1921.
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.