Estonia is a nation in Northern Europe, formally known as the Republic of Estonia (Estonian: Eesti Vabariik). It is bounded to the north by Finland's Gulf of Finland, to the west by Sweden's Baltic Sea, to the south by Latvia, and to the east by Lake Peipus and Russia. Estonia's territory includes the mainland, the bigger islands of Saaremaa and Hiiumaa, and over 2,200 smaller islands and islets off the Baltic Sea's eastern coast, totaling 45,339 square kilometers (17,505 sq mi). Tallinn, the capital city, and Tartu are the two major cities in Estonia. The Estonian language is the country's autochthonous and official language; it is the first language of the majority of the country's inhabitants and the world's second most spoken Finnic language.
Humans have been present in what is now modern Estonia since at least 9,000 BC. Following the Papal-sanctioned Livonian Crusade in the 13th century, the medieval indigenous people of Estonia were one of Europe's last "pagan" civilizations to accept Christianity. In the mid-nineteenth century, after centuries of repeated administration by the Teutonic Order, Denmark, Sweden, and the Russian Empire, a unique Estonian national identity started to form. This culminated in the Estonian Declaration of Independence from the then-warring Russian and German Empires on February 24, 1918, and, following the end of World War I, in the 1918–1920 War of Independence, in which Estonians successfully repelled the Bolshevik Russian invasion and defended their newborn freedom. Estonia maintained neutrality at the outset of World War II, but the nation was frequently challenged, invaded, and occupied, first by the Stalinist Soviet Union in 1940, then by Nazi Germany in 1941, and then reoccupied and absorbed into the USSR as an administrative component in 1944. (Estonian SSR). After losing its de facto independence to the Soviet Union, diplomatic representations and the government-in-exile ensured Estonia's de jure state continuation. Following the bloodless "Singing Revolution" of 1988–1990 in Estonia, the country's de facto independence was restored on August 20, 1991.
Estonia is a developed nation with a high-income advanced economy and a high Human Development Index score. Estonia is a democratic unitary parliamentary republic that is administratively organized into 15 maakonds (counties). It is one of the least populated members of the European Union, the Eurozone, the OECD, the Schengen Area, and NATO, with a population of little more than 1.3 million. Estonia has frequently rated well in worldwide rankings for quality of life, education, journalistic freedom, digitalization of government services, and the presence of technology firms.