[1] All three Baltic countries are classified as high-income economies by the World Bank and maintain a very high Human Development Index.

With the advent of Foreningen Norden (the Nordic Associations), the term Baltic countries was no longer used for Sweden and Denmark.

[6][better source needed][7] After World War II (1939–1945), the term has been used to group the three countries that were occupied by the Soviet Union until 1991: Estonia, Latvia, and Lithuania.

Kievan Rus sought to conquer them, and in the 11th century took control of some lands; Orthodoxy began to spread.

The Grand Duchy of Lithuania concluded the Union of Krevo with the Kingdom of Poland in 1385 and together resisted the advance of the orders to the east.

Due to the threat of Russia, the Grand Duchy of Lithuania and Kingdom of Poland formed the Union of Lublin in 1569 as the Polish-Lithuanian Commonwealth.

From 16th to 18th centuries the united Polish–Lithuanian state fought with Denmark, Russia and Sweden for Estonian and Latvian lands in the Livonian and Northern wars.

In the middle of 17th century, Sweden conquered and founded the governorates of Estonia and Livonia (with the exception of Courland, Latgale).

After the Great Northern War, both governorates became part of the Russian Empire, during the partitions of the Polish–Lithuanian Commonwealth, Russia also annexed Courland, Latgale, and all of Lithuania.

Estonians and Latvians, ruled by the German orders, Poland–Lithuania, Sweden, and Russia for numerous centuries, managed to preserve their language and culture.

Estonia had already obtained autonomy from tsarist Russia in 1917, and declared independence in February 1918, but was subsequently occupied by the German Empire until November 1918.

[10][11] All three Baltic countries experienced a period of authoritarian rule by a head of state who had come to power after a bloodless coup: Antanas Smetona in Lithuania (1926–1940), Kārlis Ulmanis in Latvia (1934–1940), and Konstantin Päts during the "Era of Silence" (1934–1938) in Estonia, respectively.

In June 1940, the Red Army occupied all of the territory of Estonia, Latvia, and Lithuania, and installed new, pro-Soviet puppet governments.

[citation needed] During the occupation the Nazi authorities carried out ghettoisations and mass killings of the Jewish populations in Lithuania and Latvia.

[20] During the Cold War, Lithuania and Latvia maintained legations in Washington DC, while Estonia had a mission in New York City.

[citation needed] Skrunda-1, the last Russian military radar in the Baltics, officially suspended operations in August 1998.

[23] All three are today liberal democracies, with unicameral parliaments elected by popular vote for four-year terms: Riigikogu in Estonia, Saeima in Latvia and Seimas in Lithuania.

Each of the three countries has declared itself to be the restoration of the sovereign nation that had existed from 1918 to 1940, emphasizing their contention that Soviet domination over the Baltic states during the Cold War period had been an illegal occupation and annexation.

At least formally, most Western democracies never considered the three Baltic states to be constituent parts of the Soviet Union.

[24] Other exceptions included Sweden, which was the first Western country, and one of the very few to ever do so, to recognize the incorporation of the Baltic states into the Soviet Union as lawful.

On 8 November 1991, the Baltic Assembly, which includes 15 to 20 MPs from each parliament, was established to facilitate inter-parliamentary cooperation.

All three countries are also members of the New Hanseatic League, an informal group of northern EU states formed to advocate a common fiscal position.

New macroeconomic requirements have arisen for them; the Maastricht criteria became obligatory and later the Stability and Growth Pact set stricter rules through national legislation by implementing the regulations and directives of the Sixpack, because the financial crisis was a shocking milestone.

These included the development of the Būtingė oil terminal, electricity interconnections with Sweden (NordBalt), Finland (Estlink) and Poland (LitPol Link), the Klaipėda LNG terminal, Gas Interconnection Poland–Lithuania and the Inčukalns underground gas storage facility.

The current divide between Lutheranism to the north and Catholicism to the south is the remnant of Swedish and Polish hegemony, respectively, with Orthodox Christianity remaining the dominant religion among Russian and other East Slavic minorities.

[citation needed] Because the three countries had been independent nations prior to their occupation by the Soviet Union, there was a strong feeling of national identity (often labeled "bourgeois nationalism" by the Communist Party) and popular resentment towards the imposed Soviet rule in the three countries, in combination with Soviet cultural policy, which employed superficial multiculturalism (in order for the Soviet Union to appear as a multinational union based on the free will of its peoples) in limits allowed by the communist "internationalist" (but in effect pro-Russification) ideology and under tight control of the Communist Party (those of the Baltic nationals who crossed the line were called "bourgeois nationalists" and repressed).

[citation needed] The question of assimilation, or integration, of the Russian-speaking immigrants is a major factor in current social and diplomatic affairs.

[38] Since the decline of Russian influence and integration into the European Union economy, English has become the most popular second language in the Baltic states.

[44] Terms related to modern name Baltic appear in ancient texts, but had fallen into disuse until reappearing as the adjective Baltisch in German, from which it was adopted in other languages.

All three are unitary republics, which simultaneously joined the European Union on 1 May 2004, share EET/EEST time zone schedules and the euro currency.