Bulgaria is a country in southeastern Europe. Its official name is the Republic of Bulgaria. It is bounded to the north by Romania, to the west by Serbia and Macedonia, to the south by Greece and Turkey, and to the east by the Black Sea. Bulgaria is Europe’s 16th-largest nation, with a land area of 110,994 square kilometers (42,855 square miles).
During the Neolithic era, organized ancient civilizations started to emerge in present Bulgarian territories. Thracians, Greeks, and Romans were all present throughout its ancient history. The formation of an united Bulgarian state may be traced back to the creation of the First Bulgarian Empire in 681 AD, which controlled much of the Balkans and served as a cultural center for Slavs throughout the Middle Ages. After the collapse of the Second Bulgarian Empire in 1396, its lands were ruled by the Ottomans for almost five centuries. The Third Bulgarian State was established as a result of the Russo-Turkish War in 1877–78. Several confrontations with its neighbors ensued in the years that followed, prompting Bulgaria to side with Germany in both world wars. As part of the Soviet-led Eastern Bloc, it became a one-party socialist state in 1946. The governing Communist Party permitted multi-party elections in December 1989, paving the way for Bulgaria’s transition to democracy and a market-based economy.
Bulgaria’s 7.4 million-person population is mostly urbanized and centered in the administrative centers of its 28 regions. The capital and biggest city, Sofia, is the focal point of most economic and cultural activity. Heavy manufacturing, power engineering, and agriculture are the strongest sectors of the economy, all of which depend on local natural resources.
The present political system of the nation goes back to the adoption of a democratic constitution in 1991. Bulgaria is a unitary parliamentary republic with strong political, administrative, and economic centralization. It is a member of the European Union, NATO, and the Council of Europe; a founding member of the Organization for Security and Cooperation in Europe (OSCE); and a three-time member of the United Nations Security Council.