Guinea's mineral wealth makes it potentially one of Africa's richest countries, but its people are among the poorest in West Africa.
Experiments with socialism and a two-year rule by junta have taken their toll on prospects for development. The 2010 election ushered in civilian rule, but led to violent ethnic clashes as well.
In addition, hundreds of thousands of refugees from Liberia and Sierra Leone have strained Guinea's struggling economy.
The instability has generated suspicion and ethnic tension - as well as accusations between neighbours of attempts at destabilisation and border attacks.
The Republic of Guinea
Population 10.5 million
Area 245,857 sq km (94,926 sq miles)
Languages French, Susu, Fulani, Mandingo
Religions Islam, Christianity, indigenous beliefs
Life expectancy 53 years (men), 56 years (women)
Currency Guinean franc
President: Alpha Conde
Alpha Conde became president in 2010 after a lifelong battle against a series of despotic and military regimes which sent him into exile and prison. It was Guinea's first democratic election since gaining independence from France in 1958.
However, the vote kindled ethnic tensions, as Mr Conde hails from the Malinke ethnic group, which makes up 35% of the population. The defeated, Cellou Dalein Diallo, is a member of the Peul ethnic group, to which 40% of Guineans belong.
Mr Diallo has repeatedly accused the president of sidelining his constituents, including many Peul.
Both allies and critics alike acknowledge his charisma and intelligence, but some also describe him as authoritarian and impulsive, someone who rarely listens to others and often acts alone.
His supporters however consider him untainted, a "new man" who has never had the opportunity to "participate in the looting of the country."
He was elected for a second term in 2015, but faced protests four years later when he tried to change the constitution and run for a third term.
Some key dates in Guinea's history:
1891 - France declares Guinea to be a colony, separate from Senegal.
1958 - Guinea becomes independent, with Ahmed Sekou Toure as president.
2000 - Start of incursions by rebels in Guinea's border regions with Liberia and Sierra Leone which eventually claim more than 1,000 lives and cause massive population displacement. The government accuses Liberia, the Sierra Leonean United Revolutionary Front (RUF) rebel group, Burkina Faso and former Guinean army mutineers of trying to destabilise Guinea.
2003 - President Lansana Conte wins a third term in elections boycotted by the opposition.
2008 - Military seizes power after President Conte dies. The coup meets with international condemnation, but many Guineans back the army's move.
2010 - Return to civilian rule. Alpha Conde declared winner of run-off presidential race. Emergency declared after clashes between security forces and supporters of defeated candidate Cellou Dalein Diallo.
2014 - Outbreak of the deadly Ebola virus in southern Guinea. It spreads to Liberia and Sierra Leone, killing 11,300 people in two years.