Sweden–Russia border The first treaty concerning the border was signed in
Nöteborg in 1323 between
Sweden (to which Finland belonged) and the
Novgorod Republic. The
Treaty of Teusina in 1595 moved the border eastward. As a result of the
Ingrian War and the resulting
Treaty of Stolbovo (1617), Sweden gained a large tract of land through the acquisition of the
Nöteborg fortress,
Kexholm and its large province, southwest Karelia and the province of
Ingria. The
Treaty of Nystad in 1721 and the
Treaty of Åbo in 1743 moved the border westward. The population of the border region was marked by religious differences, with the Russian side being predominantly
Orthodox, while the Swedish side was initially
Catholic, and later,
Lutheran Protestant. After the
peace of Stolbovo in 1617, the Orthodox population faced persecution and many fled to the Russian side or converted to Lutheranism. The displaced population was largely replaced by immigrants from Finland, most of whom were
Savonians who spoke
Finnish instead of the closely related
Karelian.
Border of the Grand Duchy of Finland After the
Finnish War, the
Treaty of Fredrikshamn transferred Finland from Sweden to the
Russian Empire with the establishment of the
Grand Duchy of Finland, an autonomous state ruled by the Russian Emperors. In 1812, the
Vyborg Governorate, also known as "Old Finland", was incorporated into the new Grand Duchy. A customs border was set up between the Grand Duchy and Russia, making Finland its own customs territory. The
Finnish Customs Department was officially established on February 18, 1812. The customs border was primarily for Russia's benefit, but it gave Finland the crucial ability to use its own customs revenue and set its own tariffs. By the early 20th century, customs had become the Grand Duchy's most significant source of tax revenue, accounting for about three-quarters of state income. Efforts to unify the Finnish and Russian customs services and remove the border failed due to internal Russian turmoil in the early 1900s. The first national atlas of Finland, '''', was published during the
period of Russification in 1899. On the map, the border with Russia was intentionally drawn in a similar style to the borders with Sweden and Norway to emphasize Finland's distinct status as a separate entity from Russia. The depiction of the border drew attention from the
Governor-General of Finland, the Russian representative in Finland, who sent a letter to the Senate and requested that the border between the Grand Duchy and Russia be marked differently from the national borders. In the 1910 edition of the atlas, this request was acknowledged by making a nearly imperceptible change to the width of the lines marking the borders with Sweden and Norway.
Finland–Soviet-Russia border in 1920: Repola and Porajärvi, occupied by the Finnish government, were returned to the Soviet Union, while Petsamo was gained by Finland. In the period following Finland's
declaration of full independence in 1917, during the
Finnish Civil War and
Russian Civil War, Finnish activists often crossed the border into Soviet territory in order to fight in the "
heimosodat" wars surrounding Finnish ethnic self-determination and possible annexation into Finland. This ended in 1920 when the Russian–Finnish
Treaty of Tartu in 1920 defined Finland as an independent country and established the border between the two countries. Despite this, Finnish fighters took part in the
East Karelian uprising and Soviet–Finnish conflict of 1921–22. In 1922, the Finnish government closed the border to volunteers and food and munitions shipments.
Changes to borders with World War II In 1939, the
Soviet Union invaded Finland in the
Winter War, leading to the signing of the
Moscow Peace Treaty the following year. The treaty had Finland cede several border areas to the USSR. The naval border was established in 1940 and more accurately defined in 1965. In 1940 and 1941, the Soviet Union rented
Hanko Peninsula as a
military base, thereby creating an additional border crossing leading to the exclave. After the
Continuation War (1941–44), the land border was demarcated in the
Treaty of Paris (1947). As a result, approximately half of
Finnish Karelia (including Finland's fourth-largest city
Vyborg), parts of
Salla, and all of
Petsamo were ceded to the Soviet Union. The new border cut through what was previously Finnish territory, severing many rail lines and isolating many Karelian towns from Finland. The Soviet Union demanded the territories be emptied, and Finns
were subsequently evacuated from the area and resettled in Finland. The areas that they left were then settled by Soviet immigrants. In the
Moscow Armistice signed in 1944 between Finland, the Soviet Union and the United Kingdom, a small peninsula towards the Gulf of Finland,
Porkkala, was rented to the Soviet Union as a military base. This created in effect a southern border crossing to the Soviet
exclave. Border crossings were in and . In 1947, Finnish trains were allowed to pass through the base, but the passenger car windows were blacked out and the
locomotives replaced while crossing through. Porkkala was returned to the Finnish government in 1956.
Soviet–Finnish border during the Cold War During the
Cold War, the border constituted part of the perimeter of the
Iron Curtain. Crossing the border was not possible for much of its length. Only a very limited number of border crossing points existed, and the Soviet government permitted only escorted trips to select cities; border zones were off limits to tourists. There was little contact between cities that were relatively close to each other on opposite sides of the border, such as
Imatra and
Svetogorsk. The Soviet side maintained extensive electronic systems and patrols to prevent illegal crossings. Soviet border
surveillance began at a great distance from the actual border, and was as extensive as elsewhere along the Iron Curtain. The first surveillance systems were installed in
railway stations in cities, where the
militsiya monitored potentially suspicious traffic. The
border zone began at from the border. A special permit was required for entry, and the first line of control was equipped with electronic alarms. At , there was a raked sand strip (to detect footprints) and a thin alarmed
tripwire. At , there was a tall barbed wire fence, with a top that curved inwards towards their own territory to prevent Soviet citizens from leaving. The fence had an electronic alarm system. However, it was not protected underground and tunnelling under it was possible. At the international border, there was a
border vista. On the Finnish side, there was a
border zone where entry was allowed only with a permit. In Northern Finland, there was a reindeer fence intended to prevent privately owned
reindeer from crossing, but this was not designed as an obstacle to persons. Since Finland was a
neutral country for most of the Cold War, they did not protect illegal border crossers and instead returned them to the Soviet authorities if captured. As a result, illegal border crossers had to arrive in a third country, for example Sweden, in order to defect to the
West. Both states verified the inviolability of borders and territorial integrity in the first
Conference on Security and Co-operation in Europe in 1975. ==Infrastructure==