Finland is a Nordic country in Northern Europe, officially known as the Republic of Finland. It is bordered on the west by Sweden, on the east by Russia, and on the north by Norway, and is characterized on the west by the Gulf of Bothnia and on the south by the Gulf of Finland of the Baltic Sea, which runs through Estonia. Finland has a population of 5.5 million people and a land area of 338,455 square kilometers. Helsinki is the capital and largest city of Finland. The Finns' native language, Finnish, is one of only a few Finnic languages spoken around the world. The climate varies according to latitude, ranging from the warm continental climate in the south to the cold boreal climate in the north. Finland was first settled around 9000 BC, after the Last Glacial Period, and is predominantly a boreal forest biome with over 180,000 lakes. Several distinct ceramic types and cultures emerged during the Stone Age. In Fennoscandia and the Baltic region, the Bronze and Iron Ages were marked by extensive interaction with other cultures. As a result of the Northern Crusades, Finland eventually became an integral part of Sweden starting in the late 13th century. Finland was annexed by Russia as the independent Grand Duchy of Finland in 1809 as a result of the Finnish War, during which time Finnish art flourished and the notion of independence started to take root. Finland was the first European country to offer universal suffrage in 1906, and the first country in the world to allow all adult people to run for public office. Nicholas II, Russia's last Tsar, attempted to russify Finland and end its political sovereignty, but Finland declared independence from Russia after the 1917 Russian Revolution. The Finnish Civil War shattered the fledgling state in 1918. Finland fought the Soviet Union in the Winter War and the Continuation War, as well as Nazi Germany in the Lapland War, during World War II. Finland lost parts of its territories as a result of the wars, but it retained its independence. Until the 1950s, Finland was largely an agrarian region. Following WWII, the nation quickly industrialized and advanced its economy, while also establishing a large welfare state based on the Nordic model, resulting in widespread prosperity and a high per capita income. Finland became a member of the United Nations in 1955 and declared its neutrality. Finland joined the Organization for Economic Cooperation and Development (OECD) in 1969, the NATO Partnership for Peace in 1994, the European Union in 1995, the Euro-Atlantic Partnership Council in 1997, and the Eurozone in 1999. Finland ranks first in many national performance indicators, including education, economic competitiveness, civil liberties, quality of life, and human growth. Finland was ranked first in the World Human Capital and Press Freedom Indexes in 2015, as well as the world's most stable nation in the Fragile States Index from 2011 to 2016, and second in the Global Gender Gap Report.