Its transition to democracy and a market economy after the collapse of communism has not been easy and the country is striving to boost low standards of living.
Throughout the early 1990s Bulgaria was wracked by political instability and strikes. The former communists were a powerful influence. Although the end of the decade was more stable, there was little tangible progress with economic reform.
Under Bulgaria's former king, Simeon II, who was prime minister between 2001 and 2005, the country pressed ahead with market reforms designed to meet EU economic targets.
It achieved growth, saw unemployment fall from highs of nearly 20% and inflation come under control, but incomes and living standards remained low.
Rila monastery: National symbol has world heritage status
Bulgaria was not among the countries invited to join the EU in 2004. However, it signed an EU accession treaty in April 2005 and joined in January 2007.
EU officials set tough entry requirements, reflecting their concerns about corruption and organised crime. After a series of reports found that the Bulgarian government had failed to tackle these issues effectively, the EU announced in July 2008 that it was suspending aid worth hundreds of millions of euros.
In September 2010, the EU again called on Bulgaria to take urgent action to tackle crime and corruption, and later in the year France and Germany announced that they would block Bulgaria from joining the Schengen passport-free zone until the country had made "irreversible progress" in this area.
Another cause of friction has been the Kozloduy nuclear power plant, which supplies over a third of Bulgaria's electricity.
Amid concerns over the safety of communist-era nuclear facilities, four of Kozloduy's six reactors were shut down as a price for Bulgaria's EU membership, two of them closing just minutes before the country joined the EU.
In a bid to offset the loss of production at Kozloduy and restore its position as a major power exporter in the Balkans, Bulgaria revived plans for a second nuclear power plant, though these were later put on hold because of a lack of funds.
Bulgaria is also involved in two rival gas pipeline projects: Russia's South Stream pipeline and the EU-backed Nabucco pipeline.
Rosen Plevneliev, the outgoing construction minister, won the presidential elections in a run-off in October 2011, beating Socialist candidate Ivaylo Kalfin.
He took office in January 2012 for a five-year term in a post that carries few real powers.
As the ruling GERB party candidate, Mr Plevneliev's victory was expected to provide a boost to Prime Minister Boiko Borisov before parliamentary elections in 2013, and bolster the government's push for painful economic reforms.
Election observers expressed some concerns at reports of vote-buying and also at anti-Roma rhetoric by nationalist candidates in the wake of ethnic clashes in the south of the country in September.
Prime minister: Boiko Borisov
The centre-right GERB party led by Sofia mayor Boiko Borisov was the clear winner in general elections held in July 2009.
Voters punished the Socialist-led governing coalition of Sergei Stanishev for failing to crack down on corruption and organised crime.
Mr Borisov's poll campaign centred on promises to jail corrupt officials and mafia bosses and pull the country out of its worst economic downturn in years.
Mr Borisov is a black belt and former coach of the national karate team, who began his career as a fireman in Communist Bulgaria. He created a private security company in the early 1990s and was bodyguard to both the ousted dictator Todor Zhivkov and to exiled Bulgarian king Simeon Saxe-Coburg-Gotha.
After Mr Saxe-Coburg-Gotha became prime minister in 2001, he appointed Mr Borisov to one of the top jobs in the Interior Ministry.
While there, Mr Borisov earned himself the image of a tough operator, but his critics accused him of populism, arguing that his well-publicised actions did not result in a serious crackdown on organised crime.
He was elected an MP in 2005, but resigned his seat, opting to run successfully for mayor of the capital Sofia several months later. He formed GERB (Citizens for European Development of Bulgaria) the following year.
As leader of the new government, Mr Borisov faced the task of changing Bulgaria's image as one of Europe's most corrupt countries in the middle of an economic crisis.
Global media giants have a stake in Bulgaria's lively broadcasting market. Balkan News Corporation - part of News Corporation - operates bTV, the country's first national commercial channel. A Scandinavian group operates national station Nova TV. A third national network, TV2, is Bulgarian-owned.
There are several private regional TV channels and many private radio stations. Freedom of the press is guaranteed under the constitution.
In 2009, Paris-based Reporters Without Borders warned that investigative journalism and media pluralism were "seriously threatened" by organised crime and pressure from political and business quarters.
Some 3.4 million Bulgarians were online by June 2010. (Internetworldstats).
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