North Karelia in the context of "Ladoga Karelia"

The Winter War was a war between the Soviet Union and Finland. It began with a Soviet invasion of Finland on 30 November 1939, three months after the outbreak of World War II, and ended three and a half months later with the Moscow Peace Treaty on 13 March 1940. Despite superior military strength, especially in tanks and aircraft, the Soviet Union suffered severe losses and initially made little headway. The League of Nations deemed the attack illegal and expelled the Soviet Union from its organization.

The Soviets made several demands, including that Finland cede substantial border territories in exchange for land elsewhere, claiming security reasons — primarily the protection of Leningrad, 32 km (20 mi) from the Finnish border. When Finland refused, the Soviets invaded. Most sources conclude that the Soviet Union had intended to conquer all of Finland, and cite the establishment of the puppet Finnish Communist government and the Molotov–Ribbentrop Pact's secret protocols as evidence of this, while other sources argue against the idea of a full Soviet conquest. Finland repelled Soviet attacks for more than two months and inflicted substantial losses on the invaders in temperatures as low as −43 °C (−45 °F). The battles focused mainly on Taipale along the Karelian Isthmus, on Kollaa in Ladoga Karelia and on Raate Road in Kainuu, but there were also battles in Lapland and North Karelia.

South Karelia (or Southern Karelia, Finnish: Etelä-Karjala; Swedish: Södra Karelen; Karelian: Suvi-Karjala) is a region of Finland. It borders the regions of Kymenlaakso, South Savo and North Karelia, as well as Russia (Republic of Karelia and Leningrad Oblast).

Kainuu (Finnish pronunciation: [ˈkɑi̯nuː]; Swedish: Kajanaland) is one of the 19 regions of Finland (Finnish: maakunta; Swedish: landskap). Kainuu borders the regions of North Ostrobothnia, North Savo and North Karelia. In the east, it also borders Russia (Republic of Karelia).

Culturally, Kainuu is part of the larger Eastern-Finnish cultural heritage. The dialect of Kainuu resembles Savonian and Karelian dialects.

South Savo (or Southern Savonia; Finnish: Etelä-Savo; Swedish: Södra Savolax) is a region in the south-east of Finland. It borders the regions of North Savo, North Karelia, South Karelia, Kymenlaakso, Päijät-Häme, and Central Finland. The total area of South Savo is 18,768.33 km (7,246.5 sq mi), with a population of 153,738 (2011). South Savo is located in the heart of the Finnish lake district, and contains Lake Saimaa, the largest lake in Finland. The three major towns in the region are Mikkeli, Savonlinna and Pieksämäki.

Karelia (/kəˈriːliə, kəˈriːljə/; Karelian and Finnish: Karjala [ˈkɑrjɑlɑ]; Livvi: Karjal; Russian: Каре́лия, romanized: Kareliya [kɐˈrʲelʲɪjə], historically Коре́ла, Korela [kɐˈrʲelʲə]; Swedish: Karelen [kɑˈreːlen]) is an area in Northern Europe of historical significance for Russia (including the Soviet era), Finland, and Sweden. It is divided between northwestern Russia (the federal subjects of the Republic of Karelia and Leningrad Oblast) and Finland (the regions of South Karelia, North Karelia, and the eastern portion of Kymenlaakso).

Karelia (Finnish: Karjala: Swedish: Karelen) is a historical province of Finland, consisting of the modern-day Finnish regions of South Karelia and North Karelia plus the historical regions of Ladoga Karelia and the Karelian Isthmus, which are now in Russia. Historical Karelia also extends to the regions of Kymenlaakso (east of the River Kymi), North Savo (Kaavi, Rautavaara and Säyneinen) and South Savo (Mäntyharju).

Karelia may also refer to the region as a whole, including the portion of Karelia within Russia. The term "Finnish Karelia" refers specifically to the historical Finnish province, while East Karelia or "Russian Karelia" refers to the portion of Karelia within Russia. Finland ceded a portion of Finnish Karelia to the Soviet Union after the Winter War of 1939–40. More than 400,000 evacuees from the ceded territories re-settled in various parts of Finland. Finnish Karelians include the present-day inhabitants of South Karelia and North Karelia, as well as the still-surviving evacuees from the ceded territories.

North Savo (or Northern Savonia; Finnish: Pohjois-Savo; Swedish: Norra Savolax) is a region in eastern Finland. It borders the regions of South Savo, Central Finland, North Ostrobothnia, Kainuu, and North Karelia. Kuopio is the largest city in the region and Lake Kallavesi is the largest lake in the region.

The region's traditional food is a fish and bacon filling pie called Kalakukko.

Joensuu (Finnish: [ˈjoensuː] ; Karelian: Jovensuu, lit. 'river's mouth') is a city in Finland and the regional capital of North Karelia. It is located in the eastern interior of the country and in the Finnish Lakeland. The population of Joensuu is approximately 78,000, while the sub-region has a population of approximately 127,000. It is the 11th most populous municipality in Finland, and the ninth most populous urban area in the country.

Joensuu was founded in 1848 by the Russian Emperor Nicholas I during Grand Duchy of Finland period. The city is located on the northern shore of Lake Pyhäselkä, the northern part of Lake Saimaa, at the mouth of the River Pielinen. The nearest major city, Kuopio in North Savo, is located 136 kilometres (85 mi) to the west. From Joensuu, the distance to Lappeenranta, the capital of South Karelia, is 233 kilometres (145 mi) along Highway 6.