Would you like to know more about the history of Suomenlinna? This section contains information on the history of the fortress.

The Swedish era 1748-1808

Sweden lost its superpower status and its most important eastern fortresses in the wars with Russia in the first half of the 1700s. Reinforcing the defences of Finland was deemed necessary. In 1747, the Swedish parliament made a decision to build a central fortress including a naval base in Helsinki and a border fortress in Degerby, off Loviisa.

The fortification work began in the following year on the Susiluodot islands off Helsinki, the location of present-day Suomenlinna. In 1750, the fortress was named Sveaborg, rendered phonetically to Viapori in Finnish. The construction of a dry dock was launched in the fortress for building warships for the Archipelago Fleet.

Plans fail

The ambitious fortification plans had to be scaled down a few years after the construction began, and the resources were directed to building a sea fortress. The active phase of the Viapori fortification work ended just over 40 years after it began.

The fortress was actually never quite completed as planned, even though the original aim was to complete the construction in only four years. The Pomeranian war (1756–1763) put the construction on hold, although the battles did not extend to Viapori in the 1700s. The sea fortress had merits as a naval base in the Russo-Swedish War of 1788–1790 (‘Gustav III’s War’), but it was not involved in actual battles.

In 1808, Viapori was besieged by the Russian forces in the Russo-Swedish war. After just minor skirmishes, Commandant C.O. Cronstedt decided to surrender. The reasons for surrender remains an unsolved mystery. The surrendered sea fortress was taken over by the Russians, and a new era began for Viapori.

The Russian era 1808-1918

In May 1808, the Viapori fortress surrendered to the Russians, which marked a new era in the history of the fortress. After the Swedes vacated the fortress, Viapori along with its ships and equipment was transferred under the rule of the Russian Imperial Government. The following year, Finland became an autonomous Grand Duchy of Russia, but Viapori remained a military base under Russian administration.

The Russians valued the Viapori fortress and made big plans for it. The fortress perimeter was expanded to Santahamina, Kuningassaari and Vallisaari. Barracks to house soldiers were built in the fortress, and an Orthodox garrison church designed by Konstantin Ton was completed.

Viapori falling into decay and under bombardment

The military importance of the fortress declined over the course of the 1800s. The maintenance and renovation of the fortifications were neglected due to a lack of funds, and Viapori fell into decay.

It was not until the run-up to the Crimean War (1853–1856) that the condition of the fortress began to raise concerns. War broke out between Russia and Turkey, but England and France soon joined forces with the Turks. A combined Anglo-French fleet bombarded Viapori for two days in August 1855, and Viapori sustained heavy damage in the bombardment.

In the late 19th century and the early years of the 20th century, the fortifications of Viapori were repaired. However, Viapori continued to decline in importance, and ultimately it was just one Russian fortress among many.

Part of Peter the Great’s Naval Fortress

In summer 1906, inspired by revolutionary unrest in Russia, a mutiny erupted in Viapori. The mutineers attempted to bring the fortress under their control and partly succeeded. However, the mutiny was defeated in four days.

During the First World War (1914–1918), Viapori formed part of what was known as the Naval Fortress of Peter the Great, designed to protect the Russian capital St. Petersburg.

With the Russian Revolution and Finland’s independence, Viapori was taken over by the newly founded Finnish government in 1918 and renamed Suomenlinna (‘Castle of Finland’).

The Russian Viapori Online Exhibition

The Russian Viapori Online Exhibition displays Suomenlinna during its Russian period. See exhibition here.

The Finnish era 1918 ->

During the Russian era, the Viapori fortress was not part of the Finnish Grand Duchy but was governed by Russia. Finland had declared independence on 6 December 1917, but Viapori was still under the command of Russians troops for some time. It was not transferred under the administration of the Finnish government until in the spring 1918 during the Finnish Civil War.

Towards the end of the war, the Whites set up a prison camp in Viapori for Red prisoners, up to 8,000 of them. In the prison camp, Red prisoners were executed and some died of diseases due to the poor conditions in the fortress. The last prisoners were released in March 1919.

A new name for the Finnish fortress: Suomenlinna

In May 1918, the fortress was renamed Suomenlinna (‘Castle of Finland’) to reflect Finland’s independence, and it was annexed to the state of Finland. Soon, the fortress housed various Defence Forces units and Suomenlinna became a Finnish garrison.

Small-scale renovations also started gradually, and tourism to the islands took off.

During the war

When the Winter War broke out in 1939, the forces stationed on Suomenlinna included anti-aircraft and artillery units. The fortress was a base for the Finnish submarine fleet.

After the Continuation War (1941–1944), only a few military units remained in Suomenlinna.

Under civilian administration

In the mid-1960s, the Defence Forces announced that it would be vacating the fortress completely. When the Suomenlinna Coastal Artillery Regiment moved out in 1972, Suomenlinna was turned over to civilian administration. Among the Defence Forces units, only the Naval Academy remains in Suomenlinna to this day. Renovation of Suomenlinna began, and buildings were overhauled for residential use.

Suomenlinna was added to UNESCO’s World Heritage List in 1991. During the Finnish era, the fortress has developed into one of the most popular tourist attractions in Finland. In addition, Suomenlinna is one of Helsinki’s districts, a home to approximately 800 residents and a workplace for about 400 people.