Karlsborg Fortress

The largest fortress in Europe

The huge fortress on the promontory of Vanäs was begun in 1819 and completed in 1909. The fortress was the largest in Europe and was decommissioned in 1928.gen var den största i Europa och avrustades 1928.

Central defence policy

The fortress was built as part of the central defence policy, born when Sweden lost Finland and Åland to Russia in the war of 1808-09. This left Sweden's borders open and the country exposed to hostile invasion and in need of a new kind of defence. Government minister Baltzar von Platen, the man behind the Göta Canal, was on the defence committee of 1809 and proposed the building of a centrally located fortress in the heart of Sweden. The idea was that the royal family, the government, the country's gold reserves and the crown jewels could be moved to safety in the event of war. The defence debate was lively but the central defence idea was approved. In 1819 Karl XIV Johan decided that a fortress was to be built in Vanäs on the shore of Lake Vättern.

General Bengt Erland Franc-Sparre

General Bengt Erland Franc-Sparre, head of the corps of engineers, was ordered to draw up the first plans for Karlsborg. The construction work was largely carried out by prisoners. In the first years of the project the amount of earth excavated for the banks was almost equivalent to two Egyptian pyramids.

Keeping up with developments

In the nineteenth century the art of building fortresses developed quickly and plans for major defences had to be revised over and over again. Improved firepower and better land communications led to central defences such as Karlsborg becoming outdated. Fortifications moved to the coasts and to underground fortresses in the rock. The decision to build Boden Fortress in 1900 marked the abandoning of the central defence policy.

Vaults for the national bank

The most impressive part of Karlsborg Fortress is the third line of fortifications, 678 metres long, built in 1844-66. Embrasures here enabled defenders to shoot at the area beyond the moats. The walls enclosed an entire town complete with a hospital, storage areas and magazine. The fortress also included a neo-Gothic church. The third line of defences contained vaults for the national bank, which was kept there most recently during the Second World War.

Tyghuset, completed in 1830, was one of the large central stores with room for 100,000 rifles.

Karlsborg is now used by the army as a training centre and for storage.

In brief

• Built: 1819-1909
• Architect: The first plans were drawn up by General Bengt Erland Franc-Sparre, head of the corps of engineers.
• Address: Fortifikationsgatan, Karlsborg
• Manager: Gunilla Bernspång, National Property Board, Phone +46 505 451 374, E-mail gunilla.bernspang@sfv.se