Bulgaria

Bulgaria, officially the Republic of Bulgaria, lies in the eastern Balkans of Southeastern Europe, south of the Danube River and west of the Black Sea, with Sofia as its capital and largest city. The First Bulgarian Empire was established in 681 AD after the Bulgars, led by Asparukh, invaded the region; following Byzantine conquest in 1018, a Second Bulgarian Empire was founded in 1185, and Ottoman rule then lasted roughly five centuries until the Russo-Turkish War of 1877-1878 created the modern Bulgarian state, which declared full independence on 5 October 1908. After communist rule from 1946 to 1989, Bulgaria transitioned to democracy following the revolutions of that year and operates today as a unitary parliamentary republic; it joined NATO in 2004 and the European Union in 2007. Covering 110,993.6 square kilometers, the tenth largest EU member state by area, Bulgaria had a population of about 6.4 million as of December 2025, roughly 85.7 percent ethnically Bulgarian per the 2021 census, and now uses the euro as its official currency.