Fredrikstad fortress was constructed between 1663-1666 by the officer Willem Coucheron and his son Anthony Coucheron following the order of the Dano-Norwegian King Frederick II. A temporary fortification had previously been built on the site during the Torstenson War (1644-1645) between Sweden and Denmark-Norway.
The first commander was appointed 6 January 1662; he was Lieutenant Colonel Johan Eberhard Speckhan. Besides the fortress the prison works was also under the supervision of the commander of Fredrikstad fortress. In 1716 the fortress was used by the naval hero Peder Tordenskjold when he attacked the Swedish fleet during the Battle of Dynekilen.
The only time the fortress were attacked was during the Swedish-Norwegian War (1814). The fortress, under the command of Nils Christian Frederik Hals, capitulated on 4 August 1814. The fortress was closed in 1903, but continued to serve as a garrison. Fredrikstad fortress is unique in Norway by being the only fortress that is preserved as it was. The remaining military installations in Fredrikstad were closed in 2002 and today the fortress with its mix of old buildings and art exhibitions is very popular for visitors.
The fortifications in Fredrikstad include Kongsten fort, Isegran fort, Cicignon fort, Huth fort, Akerøya fort and Slevik battery.
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.