Karelians (Karelian: karjalaižet, karjalazet, karjalaiset; Finnish: karjalaiset; Swedish: kareler, karelare; Russian: карелы, romanized: karely) are a Baltic Finnic ethnic group who are indigenous to the historical region of Karelia, which is today split between Finland and Russia.

This distinction historically arose from Karelia having been fought over and eventually split between Sweden and Novgorod, resulting in Karelians being under different cultural spheres.

In Russia, Karelians mostly live in the Republic of Karelia, where they are the designated ethnic group, and in other adjacent north-western parts of the country.

During the Early Middle Ages, settlers from western Finland mixed with the local population to form the Karelian ethnic group.

In South Karelia, the number of archeological discoveries from this time period is lower, though permanent inhabitation was nonetheless present.

In North Karelia, only one archeological discovery from this time period has been found, dating to the eighth century.

In the 13th century, the Karelian relationship with Novgorod underwent significant changes, from partnership and alliance to gradual dominance by the latter.

The Swedes raided Karelian lands, began to convert the local population to Roman Catholicism and attempted to ensure their complete dominance with the foundation of castles, in 1293 at Vyborg and in 1295 at Kexholm (Käkisalmi in Finnish, Koryela in Russian chronicles), on the sites of ancient Karelian settlements.

By the late 14th century, Russian Karelians established control over White Karelia and came in conflict with the Norwegians on the peninsula of Kola.

As the struggle for power in the region continued over the next centuries the borderline between Sweden and Russia moved several times with most of the changes happening in Northern Karelia and Kainuu.

By the mid-17th century, the tension between the Lutheran Swedish government and Orthodox Karelians led to yet another conflict between Sweden and Russia.

From 1656 to 1658, Russian armed forces waged war on Karelian territories and tried to recapture them with the aid of some of the sympathizing local Orthodox population, but after two years of fighting both sides came to a stand-still.

As the Grand Duchy of Finland was formed, its inhabitants struggled to properly identify themselves ethnically, some being Finnish, some Swedish and some Karelian.

The Orthodox Karelians in North Karelia and Russia were now seen as close brethren or even a sub-group of the Finns.

As Finland gained its independence in 1917 the process of "finnisation" continued, but now even eastern Karelians were viewed as part of the Finnish nation.

As the local Karelian population was unwilling to end up under Soviet rule, over 400,000 people were evacuated across Finland's new border from the territories that were to be ceded.

After the Continuation War (1941–1944), in which Finland temporarily held most of Eastern Karelia, several thousands of Karelians chose to migrate west as Finnish forces retreated.

These include low birthrates (characteristic of the region in general) and especially Russification, due to the predominance of Russian language and culture.

[31] While their autosomal ancestry is mostly European, Karelians also carry some Siberian-related admixture (6–12 %)[31][32] commonly found in Uralic-speaking groups.

[31][33][34] Karelians share more IBD (identity-by-descent) segments with several other Uralic-speaking groups, including geographically distant ones from Volga-Ural and Siberia, than with their non-Uralic-speaking neighbours.

Karelians are found to have significant IBD sharing with some non-Uralic-speaking peoples from the same distant regions, such as the Volga Tatars, Yakuts and Evens, as well.