After the Crimean War, in which Finland was attacked as a part of the Russian empire, the people began a movement to gain independence; a fairly radical idea after being under foreign control for so many years. The opportunity for independence came in 1917 with the revolution in Russia. The Soviets soon recognized Finland, but soon after, the Finnish communists staged an uprising and the country fell into Civil War, with one side backed by the Soviets and the other backed by the Germans. The war only lasted a couple months though and soon after a republic was formed in Finland.
After a brief period of instability, more instability broke out with World War II (WWII). However, for Finland, this was more than a battle between themselves and the Soviets, who invaded them in late 1939 and by early 1940 had defeated the Finns and forced them to sign over more land. This encouraged the Finns to side with Nazi Germany in 1941, who was at the time attacking the Soviet Union. Finland became a staging point for Nazi attacks on St. Petersburg, but as the tides shifted and the Soviets pushed the Germans back, the Finns quickly made peace with the Soviets, but in the process lost lands and quickly realized they didn't want the Germans on their land so started removing them.
After WWII, Finland industrialized fairly quickly, but not after a few years of poverty. This time also experienced a mass urbanization and a diplomatic balancing act between their neighbors, the Soviet Union, and the west, who were in the middle of the Cold War.
In the 1990s, Finland joined the European Union (EU) and is in both the Euro zone and Schengen.