Due to the Northern Crusades and Swedish colonisation of some Finnish coastal areas most of the region became a part of the Kingdom of Sweden and the realm of the Catholic Church from the 13th century onwards. After the Finnish War in 1809 vast majority of the Finnish-speaking areas of Sweden were ceded to the Russian Empire (excluding the areas of the modern-day Northern Sweden where Meänkieli dialects of Finnish are spoken), making this area the autonomous Grand Duchy of Finland. The Lutheran religion dominated. Finnish nationalism emerged in the 19th century. It focused on Finnish cultural traditions, folklore and mythology, including music and—especially—the highly distinctive language and lyrics associated with it. One product of this era was the Kalevala, one of the most significant works of Finnish literature. The catastrophic Finnish famine of 1866–1868 was followed by eased economic regulations and extensive emigration.
In 1917, Finland declared independence. A civil war between the Finnish Red Guards and the White Guard ensued a few months later, with the "Whites" gaining the upper hand during the springtime of 1918. After the internal affairs stabilized, the still mainly agrarian economy grew relatively quickly. Relations with the West, especially Sweden and Britain, were strong but tensions remained with the Soviet Union. During the Second World War, Finland fought twice against the Soviet Union and defended its independence in the Winter War and in the Continuation War. In the peace settlement Finland ended up ceding a large part of Karelia and some other areas to the Soviet Union. However, Finland remained an independent democracy in North Europe.
In the latter half of its independent history, Finland has maintained a mixed economy. Since its post-World War II economic boom in the 1970s, Finland's GDP per capita has been among the world's highest. The expanded welfare state of Finland from 1970 and 1990 increased the public sector employees and spending and the tax burden imposed on the citizens. In 1992, Finland simultaneously faced economic overheating and depressed Western, Russian, and local markets. Finland joined the European Union in 1995, and replaced the Finnish markka with the euro in 2002. According to a 2016 poll, 61% of Finns preferred not to join NATO.
If confirmed, the oldest archeological site in Finland would be the Wolf Cave in Kristinestad, in Ostrobothnia. The site would be the only pre-glacial (Neanderthal) site so far discovered in the Nordic Countries, and it is approximately 125,000 years old.
The last ice age in the area of the modern-day Finland ended c. 9000 BC. Starting about that time, people migrated to the area of Finland from the South and South-East. Their culture represented mixture of Kunda, Butovo and Veretje cultures. Same time the northern Finland was inhabitet via coast of Norway. The oldest confirmed evidence of the post-glacial human settlements in Finland are from the area of Ristola in Lahti and from Orimattila, from c. 8900 BC. Finland has been continuously inhabited at least since the end of the last ice age, up to the present. The earliest post-glacial inhabitants of the present-day area of Finland were probably mainly seasonal hunter-gatherers. Among finds is the net of Antrea, the oldest fishing net known ever to have been excavated (calibrated carbon dating: ca. 8300 BC).