Bulgaria, officially the Republic of Bulgaria , a state in Southeastern Europe, borders five other countries; Romania to the north (mostly along the Danube), Serbia and the Republic of Macedonia to the west, and Greece and Turkey to the south. It is bordered by the Black Sea on the east.

Bulgaria comprises the classical regions of Thrace, Moesia, and Macedonia, whose first civilisation dates back to the 6th millennium BC. The country is the sovereign heir of the First Bulgarian Empire, which at times covered most of the Balkans and spread its culture and literature among the Slavic peoples of Eastern Europe. Centuries later, during the decline of the Second Bulgarian Empire, the country fell under five centuries of Ottoman rule. Diplomacy re-established Bulgaria as a constitutional monarchy in 1878, marking the birth of the Third Bulgarian Kingdom. After World War II, Bulgaria became a communist state and part of the Eastern Bloc.

Currently, Bulgaria functions as a parliamentary democracy under a unitary constitutional republic. The country is a member of the European Union and NATO with Sofia as its capital and largest city.

Flag

three equal horizontal bands of white (top), green, and red; note - the national emblem, formerly on the hoist side of the white stripe, has been removed