As a part of the Fennoscandian Shield's ancient Karelian craton, most of the Republic of Karelia's surficial geology is Archaean or Paleoproterozoic, dated up to 3.4 billion years in the Vodlozero block.

[23] Sweden's interest in Karelia began a centuries-long struggle with Novgorod (later Russia) that resulted in numerous border changes following the many wars fought between the two, the most famous of which is the Pillage of Sigtuna of 1187.

The Union's main goal was to improve the life of the common Karelians and additionally develop their own national identity.

[32] During the Finnish and the Russian Civil Wars the local peasantry rebelled against the new Soviet State due its Prodrazverstka policy, causing several squards of the "Whiteguard" to cross into the Karelian lands,[33] where then was organized a government that later swiftly declared independence from the Russian Soviet Federative Republic, creating the Uhtua Republic.

The regions were reclaimed by the Red Army later the same year, the Tartu peace was signed and the Karelian United Government was dissolved.

[34] In 1921, an uprising was started by the Forest Guerrillas in an attempt to gain control over Karelia yet again, but it was defeated by the Soviets shortly after.

The formal increase of the autonomy was first vetoed by People's Commissar for Nationalities of the RSFSR, but it was later accepted by the Central Committee of the Communist Party of the Soviet Union.

[40] Karelia has one of the biggest burial sites of Stalinist purges in Russia, Sandarmokh, where possibly thousands of victims were executed.

[41] After the Moscow Peace Treaty territories of the Karelian Isthmus were transferred to the newly created Karelo-Finnish Soviet Socialist Republic.

After the evacuation of Finnish Karelia, the new territories were left unpopulated, so migrants from Belarus, Ukraine, Russia, and other Soviet republics moved in.

After the beginning of World War II, mass rallies were held on the territory of the republic, at which the inhabitants of Karelia declared their readiness to stand up for the defense of the Soviet Union.

[42] On 24 June 1941, after the German army crossed Zapadnaya Dvina, Finnish president Risto Ryti announced declaration of war on the Soviet Union.

The Finnish army managed to break through Soviet defenses and cut the highway to Kondopoga in the area of the Sulazhgorsky brick factory.

On 1 October, due to the threat of encirclement, an order was received from the command to withdraw the main units defending the city.

The fighting near Petrozavodsk allowed the authorities to evacuate most of the civilian population and a significant part of the production capacities.

One of the prisoners told the Finnish historian Helga Seppel that before leaving Petrozavodsk, the invaders shot several young people for unknown reasons.

After normalization of diplomatic relations between USSR and Finland the status of the Karelo-Finnish SSR was changed back to the Karelian ASSR in 1956.

[46] Finnish was the second official language of Karelia from the creation of the Karelian Labour Commune up until the dissolution of the Soviet Union.

Despite being 0,4% of Russia's population, 65–70% of all Russian trout is grown in the Republic, 26% of iron ore pellets, 20% of paper, 12% of wood pulp and cellulose.

[84] Karelia is a region with a lot of natural resources, including metals such as gold, silver, platinum, copper and palladium.

Based on its natural and climatic conditions, the plant growing industry is focused on the production of feed for livestock, the bulk of potatoes and vegetables are grown in small forms of management.

[18] Main export products were lumber (over 50%), iron ore pellets (13–15%) paper and cardboard (6–9%) and sawn timber with (5–7%).

[18] Karelia is a strategically important railroad region due to the fact that it connects Murmansk with the rest of Russia by Kirov Railway, which was electrified in 2005.

[104] A lot is being done in the Republic of Karelia today to support the interests of more than 100 nationalities inhabiting it, including Karelians, Veps and Finns.

[106] Karelia is sometimes called "the songlands", as Karelian poems constitute most of the Karelo-Finnish epic Kalevala and many of Russian Bylinas were documented in Pudozh.

[108] After the creation of the Karelian Labour Commune many American and Canadian finns moved to Karelia and began creating new literature.

[109] Writers of the Republic of Karelia are united in public organizations: Karelian art history begun with Petroglyphs, which were created around 6,500 years ago.

[112] Karelia has become a source of inspiration for many famous artists of the 19th–20th century such as: Ivan Shishkin, Arkhip Kuindzhi, and N. K. Roerich.

[138] In 2009, the Ministry of Culture of the Russian Federation developed a digital film screening program in cities with a population of less than 500 thousand people,[139] new cinemas were built in shopping malls.

[142] The Legislative Assembly, the Government and the Periodika publishing house produce four newspapers in national languages: together with the regional organization Union of Karelian People: Newspapers are published in the districts of Karelia:[145] Kostomuksha News, Prionezhye, Olonia, Novaya Kondopoga, Belomorskaya Tribune, Ladoga-Sortavala, Kalevala News, Pudozhsky Vestnik, Suoyarvsky Vestnik, Circumpolar, Soviet White Sea, Novaya Ladoga, MuezerskLes, Call, Our life, Trust, Dialogue.