Finland was under Swedish rule from the 12th to the 19th centuries. This northern European country became an autonomous grand duchy within the Russian Empire in 1809, and gained independence in 1917. Finland fought against the Soviets during World War II, and lost a portion of its land to the Soviet Union as a result of a peace treaty signed in 1947. The collapse of the Soviet Union in 1991 opened up new possibilities for Finland and allowed the country to step out of the Cold War shadow. As part of its efforts to rapidly increase integration with Western Europe, Finland joined the EU in 1995 and now sees its interests best represented within the EU. Finland is also the only Nordic EU member to adopt the euro as the national currency. Finland has a highly industrialized economy based on abundant forest resources and technology. In the past decade, the emergence of the high-technology sector, led by Nokia (one of the world's leading mobile-phone makers and Finland's largest company), has played a key role in altering the structure of the Finnish economy.