Suomenlinna. The Finland’s Historic Sea Fortress

About a year ago, we took a ferry trip from Tallinn, Estonia, to Helsinki, Finland. We had around 10 hours to explore Helsinki. Although it was a heatwave back home, the temperature in Helsinki was about 17 degrees Celsius. The weather was quite pleasant, so after a brief walk around the city, we decided to take a ferry to Suomenlinna. This was my first encounter with Finland. While I have a decent understanding of Central and Western European history, I realised that in seeking information about this place, I am essentially learning Finnish history from scratch.

Suomenlinna is a sea fortress located on several islands off the coast of Helsinki. Also known by its Swedish name, Sveaborg (meaning Swedish Fortress), it was constructed in the 18th century when Finland was part of the Kingdom of Sweden. The fortress aimed at securing the kingdom’s eastern borders against Russian expansion. Suomenlinna, covering around 80 hectares across six islands (Kustaanmiekka, Susisaari, Iso Mustasaari, Pikku Mustasaari, Länsi-Mustasaari, and Långören), was one of the largest defensive projects in Europe and the world at the time, influenced by French fortification techniques. Suomenlinna served as the main base for the Swedish fleet in the eastern Baltic, strategically positioned at the entrance to Helsinki, making it a critical point in Sweden’s defence.

In the early 19th century, Europe was engulfed in the Napoleonic Wars. Sweden, a traditional adversary of Russia, faced a difficult geopolitical situation. In 1807, Russia, allied with France, demanded that Sweden join the continental blockade against Britain. When Sweden refused, Russia invaded Finnish territories under Swedish control. The Russian forces swiftly advanced westward, and in March 1808, they began the siege of Suomenlinna, cutting off the fortress from the rest of Sweden by sea. Despite its strong defences, the fortress’s garrison of about 6,000 soldiers faced dwindling supplies and uncertainty about further support from Sweden.

Admiral Carl Olof Cronstedt, the commander of the fortress, was under immense pressure. Morale among the soldiers was low, and supplies were running out. Realising that a prolonged siege could lead to starvation and disaster, Cronstedt decided to negotiate with the Russians. The Russian forces were well-prepared to continue the siege but were also open to negotiations to avoid unnecessary bloodshed. After weeks of talks and growing pressure from his own officers, Cronstedt eventually decided to surrender the fortress. On 3 May 1808, after brief negotiations, a surrender agreement was signed. The terms were relatively lenient – the garrison was allowed to leave with honours, and the Russians took control of the fortress without major damage. The surrender of Suomenlinna was a significant blow to Sweden, effectively deciding the outcome of the war. It opened the way for further Russian expansion into Finland. After the surrender, Russia quickly took control of the rest of Finland. Finland was officially annexed to the Russian Empire as an autonomous Grand Duchy. Under Russian rule, the fortress was expanded and modernised. The Russians added new fortifications and storage facilities to meet modern defensive needs, incorporating new military architecture and technology into the existing Swedish structures. The fortress also served as a military base and a prison for political prisoners.

After Finland declared independence in December 1917, the country was deeply divided, leading to civil war between the Whites and the Reds, each with different visions for Finland’s future. The Whites were conservative republicans, mainly from the middle class, landowners, the bourgeoisie, and officers, supported by wealthier farmers and intellectuals. They sought to establish a strong, independent Finnish state based on national and republican values, while maintaining traditional social and economic structures. They received crucial support from Germany, including military equipment, advisors, and troops. The Reds were a socialist and leftist movement drawn from the working class, poorer farmers, and radical intellectuals. They represented those who experienced deep social inequality and sought radical reforms to create a more just society. They aimed to establish workers’ rule and a socialist economic system inspired by the Russian Revolution of 1917, advocating for the state takeover of property, broad workers’ rights, and political reforms.

Suomenlinna played a key role in these events. During the civil war, it was seized by the Whites and used as a military base and stronghold. After the Whites won the conflict in May 1918, Suomenlinna was turned into a prisoner-of-war camp, holding mainly Red soldiers and those suspected of supporting the socialist movement. The camp’s harsh conditions, overcrowding, lack of food, and medical supplies led to high mortality among the prisoners. A place once symbolising resistance and strength had become a site of suffering and tragedy.

During World War II, Suomenlinna again served a military role, acting as a base for Helsinki’s air defence and a command post. Its strategic location at the capital’s entrance made it a critical element in Finland’s defence against Soviet bombings.

Today, Suomenlinna is known for its diverse architecture, reflecting its long history and the influences of various powers. The fortress includes many bastions, defensive walls, forts, and historic buildings, such as warehouses, barracks, and workshops. It is not only a tourist attraction but also a residential area with about 800 inhabitants. The fortress hosts numerous cultural events, including concerts, exhibitions, and festivals. Besides its historical significance, Suomenlinna offers beautiful landscapes. The fortress is easily accessible from central Helsinki, with regular ferries departing from Kauppatori square. In summer, tourist cruises also offer the chance to admire the fortress from the sea.


Suomenlinna. The Finland’s Historic Sea Fortress

Finland’s relations with Russia shortly explained

Our trip to Helsinki was brief. After four busy days on the road exploring the Baltic states, we spent a few days in Tallinn, Estonia’s capital. To reach Helsinki, the capital of Finland, you just take a ferry, and in about three hours, you’re there. It was my first time in Finland, and my understanding of the country was quite basic. Because of my work, I had some idea of its geography and transport system. I was neither surprised seeing people bathing in a swimming pool on the Baltic shore by 17 degrees Celsius, coming in and out of the sauna. Saunas are the Finnish speciality (obviously). I knew the indigenous people in this country were Sami people.

And … I knew that Finland’s relations with Russia through its history were tough (or at least I thought I knew). But that in the main square of Helsinki I would see a statue of a Russian Tsar, and hear that he was loved in this country was more than unexpected.

Statue of Alexander II, Helsinki, Finland. The statue is localised in front of the Helsinki Cathedral.

In one day you cannot learn a country or its history. But as for three hours I left my company with a goal to visit the National Museum of Finland, going through its exhibitions I caught a bit the overall historical contex. Now with plenty of photos made there, with a prospect of visiting Finland once more, it is time to connect the dots.

In the medieval period, Sweden had a significant influence on the region, with the Kingdom of Sweden establishing control over Finland in the 13th century. The area remained under Swedish rule for several centuries. Following the Russo-Swedish War from 1808 to 1809, Finland was ceded from Sweden to Russia. Surprisingly, Finland’s relations with Russia became positive. Tsar Alexander I who ruled Russia in that time recognizing the strategic benefits of possessing Finland, decided to grant it extensive autonomy, establishing the Grand Duchy of Finland as an autonomous part of the Russian Empire. The Diet of Porvoo in 1809 was a key event, where Alexander I affirmed the rights and privileges of the Finns, promising to uphold the country’s laws and religion. This era is often seen as the beginning of a distinct Finnish national identity.

His follower, Tsar Alexander II also positively impacted Finland. His reign is often associated with a period of liberalization and national awakening in Finland. He initiated several reforms that furthered Finnish autonomy. Notably, he restored the Diet of Finland in 1863, after a long period of inactivity, and introduced the Language Ordinance of 1863, which gave Finnish equal status with Swedish. These actions were instrumental in promoting Finnish language and culture. Additionally, under his rule, Finland’s economy and infrastructure saw significant development, including the construction of the Finnish railway network. Alexander II’s era is often seen as a golden age of Finnish autonomy within the Russian Empire. Alexander II was very popular in Finland, and his assassination in 1881 was mourned in the Grand Duchy. His death marked the end of the liberal era, and subsequent Tsars, especially Nicholas II, reversed many of his policies, implementing the Russification efforts.

After Alexander II’s death, his successors initiated policies aimed at strengthening the empire’s unity. This included the Russification of Finland, a policy designed to integrate Finland more closely into the Russian Empire. These efforts involved imposing the Russian language in administration and education, and the introduction of Russian law, which eroded Finnish autonomy. Legislative powers were gradually transferred from Finnish institutions to the Russian emperor and his government. This eroded the unique position Finland had enjoyed and led to widespread resentment among the Finnish population. There was a clampdown on the Finnish press and cultural expressions that were seen as dissenting or promoting Finnish nationalism. Censorship was increased, and many Finnish cultural figures faced persecution.

In response to Russification and the suppression of their rights, Finns began to cultivate a stronger sense of national identity. This period saw the rise of Finnish nationalism, which sought to preserve Finnish culture, language, and autonomy. The resistance was mostly peaceful, focusing on cultural preservation and political lobbying. In 1905, Finns organized a general strike, demanding the restoration of the country’s autonomy and rights. The unrest in Finland coincided with the Russian Revolution. This led to the November Manifesto, in which Nicholas II restored many of the rights that had been previously revoked, including the Finnish Diet’s legislative powers. The turmoil of World War I and the subsequent Russian revolutions in 1917 provided Finland with an opportunity to seek full independence. On December 6, 1917, Finland declared its independence from Russia, which was recognized by the new Bolshevik government.

The Attack, a painting by Edvard Isto from 1899 has become an emblematic depiction of the Russification of Finland and the Finnish resistance to it. In the painting, the double-headed eagle, a symbol of the Russian Empire, is shown in a menacing posture. One of its heads tears apart the Finnish Law Book, symbolizing Russia’s disregard for Finnish autonomy and legal system. The other head is poised to strike at a female figure, Suomi-neito, the Finnish Maiden. This character is a personification of Finland, often depicted as a young woman in national iconography, representing the nation itself. The imminent attack on Suomi-neito by the eagle is a metaphor for the threat posed by Russian policies to Finnish national identity and autonomy.

Shortly after the outbreak of World War II, the Soviet Union invaded Finland in November 1939, leading to the Winter War. Despite being heavily outnumbered, Finland put up a strong resistance. The war ended in March 1940 with the Moscow Peace Treaty, wherein Finland ceded approximately 11% of its territory to the Soviet Union but maintained its sovereignty. With the invasion of the Soviet Union by Nazi Germany in June 1941, Finland’s relations with Russia got yet more complicated, as Finland saw an opportunity to reclaim lost territories joining German foces. Although initially successful, the tide of the war turned, and Finland sought peace with the Soviet Union in 1944, leading to the Armistice of Moscow and later the Paris Peace Treaty in 1947. Finland was required to cede additional territories, pay reparations, and undertake to limit its armed forces. To maintain its sovereignty and a working relationship with the Soviet Union, Finland adopted a policy of neutrality, carefully balancing its relations between the East and the West. While Finland maintained a market economy and a democratic government, it avoided actions that could be perceived as hostile by the Soviet Union. The approach was legalised by Friendship, Cooperation, and Mutual Assistance Treaty signed in 1948 between Finland and the Soviet Union.

The end of the Cold War and the dissolution of the Soviet Union in 1991 removed the primary threat to Finland’s security and allowed it to pursue a more active role in international affairs, including joining the European Union and participating in NATO’s Partnership for Peace program though it remained for long time outside of NATO. Ultimately Finland joined NATO on 4 April 2023 following Russia’s aggression against Ukraine in February 2022.

Relations between Finland and Russia remain tense. Russia has been expanding its military infrastructure near the Finnish border, prompting Helsinki to bolster its own defences. The eastern border remains closed, with Finland accusing Russia of weaponising migration as a means of political pressure. Despite the strain, Finnish leaders, including President Alexander Stubb, have expressed a cautious openness to restoring ties in the future, contingent on the end of the war in Ukraine and Russia’s adherence to international law.

Finland’s relations with Russia shortly explained