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:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.