The history of Finland begins around 9,000 BC during the end of the last glacial period. Stone Age cultures were Kunda, Comb Ceramic, Corded Ware, Kiukainen, and Pöljä cultures. The Finnish Bronze Age started in approximately 1,500 BC and the Iron Age started in 500 BC and lasted until 1,300 AD. Finnish Iron Age cultures can be separated into Finnish proper, Tavastian and Karelian cultures. The earliest written sources mentioning Finland start to appear from the 12th century onwards when the Catholic Church started to gain a foothold in Southwest Finland.
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, Finland was ceded to the Russian Empire, 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 World War II, Finland fought twice against the Soviet Union, first defending its independence in the Winter War and then invading the Soviet Union 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.