Bulgaria, officially the Republic of Bulgaria, is a country in Southeast Europe. It lies on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedonia to the west, Greece and Turkey to the south, and the Black Sea to the east. Bulgaria is the sixteenth-largest country in Europe. Sofia is the nation’s capital and largest city; other major cities are Plovdiv, Varna and Burgas.

One of the earliest societies in the lands of modern-day Bulgaria was the Neolithic Karanovo culture, which dates back to 6,500 BC. In the 6th to 3rd century BC the region was a battleground for ancient Thracians, Persians, Celts and Macedonians; stability came when the Roman Empire conquered the region in 45 AD.

Bulgaria is a parliamentary democracy where the prime minister is the head of government and the most powerful executive position. The political system has three branches—legislative, executive and judicial, with universal suffrage for citizens at least 18 years old. The Constitution also provides possibilities of direct democracy, namely petitions and national referenda.
Resource: https://en.wikipedia.org/wiki/Bulgaria