Civil wars and militia conflicts have plagued the Republic of Congo, which is sometimes referred to as Congo Brazzaville.
After three coup-ridden but relatively peaceful decades of independence, the former French colony experienced the first of two destructive bouts of fighting when disputed parliamentary elections in 1993 led to bloody, ethnically-based fighting between pro-government forces and the opposition.
A ceasefire and the inclusion of some opposition members in the government helped to restore peace.
But in 1997 ethnic and political tensions exploded into a full-scale civil war, fuelled in part by the prize of the country's offshore oil wealth, which motivated many of the warlords.
The army split along ethnic lines, with most northern officers joining President Denis Sassou Nguesso's side, and most southerners backing the rebels. These were supporters of the former president, Pascal Lissouba, and his prime minister, Bernard Kolelas, who had been deposed by President Sassou Nguesso in 1997.
By the end of 1999 the rebels had lost all their key positions to the government forces, who were backed by Angolan troops. The rebels then agreed to a ceasefire.
Remnants of the civil war militias, known as Ninjas, are still active in the southern Pool region. Most of them have yet to disarm and many have turned to banditry.
The Republic of Congo is one of sub-Saharan Africa's main oil producers, though 70 percent of the population lives in poverty. Oil is the mainstay of the economy and in recent years the country has tried to increase financial transparency in the sector.
In 2004 the country was expelled from the Kimberley Process that is supposed to prevent conflict diamonds from entering the world supply market. This followed investigations which found that the Republic of Congo could not account for the origin of large quantities of rough diamonds that it was officially exporting.
IMF debt relief to the country was delayed in 2006 following allegations of corruption.
President: Denis Sassou Nguesso
Denis Sassou Nguesso is one of Africa's longest-serving leaders having first come to power three decades ago.
He gained his latest seven-year term after elections in July 2009 which were boycotted by the opposition, and from which the main opposition candidate was excluded.
He was installed as president by the military in 1979 and lost his position in the country's first multi-party elections in 1992.
He returned to power in 1997 after a brief but bloody civil war in which he was backed by Angolan troops.
A French-trained paratroop colonel, Mr Sassou Nguesso is seen as a pragmatist. During his first presidency in 1979-92 he loosened the country's links with the Soviet bloc and gave French, US and other Western oil companies roles in oil exploration and production.
He abandoned the one-party system in 1992, making the ruling Congolese Workers Party (PCT) fight for its political life after more than 20 years as the sole party.
A French judge announced in May 2009 that he would launch a landmark investigation into whether Sassou Nguesso, Omar Bongo, the late president of Gabon, and Equatorial Guinea's President Teodoro Obiang Nguema plundered state coffers to buy luxury homes and cars in France.
A complaint filed by Transparency International France accused the leaders, who deny any wrongdoing, of acquiring millions of dollars of real estate in Paris and on the French Riviera and buying luxury cars with embezzled public money.
Denis Sassou Nguesso was born in a village in northern Congo in 1943. In 2006 he became chairman of the 53-nation African Union.
A chronology of key events:
1400s - Bakongo, Bateke and Sanga ethnic groups arrive in what is now the Republic of Congo.
1482 - Portuguese navigator Diogo Cao explores the coastal areas.
French rule
1880 - French explorer Pierre Savorgnan de Brazza negotiates an agreement with the Bateke to establish a French protectorate over the north bank of the Congo river.
1907 - France restricts the role of concessionaires following widespread outrage at revelations of the brutalities of forced labour.
1910 - Middle Congo, as it was known then, becomes a colony of French Equatorial Africa.
1928 - African revolt over renewed forced labour and other abuses carried out in the course of building the Congo-Ocean railway, which resulted in the death of more than 17,000 Africans.
1946 - Congo given a territorial assembly and representation in the French parliament.
1958 - Congolese vote for autonomy within the French Community.
Independence
1960 - Congo becomes independent with Fulbert Youlou as president.
1963 - Youlou forced to resign following workers' unrest; Alphonse Massamba-Debat becomes president and Pascal Lissouba prime minister.
1964 - Massamba-Debat sets up the National Revolutionary Movement as the sole party and proclaims a non-capitalist path of economic development.
1968 - Massamba-Debat ousted in a coup led by Marien Ngouabi, who continues his predecessor's commitment to socialism but sets up his own party, the Congolese Workers Party (PCT).
1970 - Ngouabi proclaims Congo a Marxist People's Republic with the PCT as the sole legitimate party.
1977 - Ngouabi is assassinated. Massamba-Debat and the Archbishop of Brazzaville, Emile Cardinal Biayenda, are killed shortly afterwards.
Joachim Yhombi-Opango becomes president.
1979 - Yhombi-Opango hands over the presidency to the PCT, which chooses Denis Sassou-Nguesso as his successor.
1981 - Congo signs treaty of friendship and cooperation with the Soviet Union.
1990 - The PCT abandons Marxism.
1992 - Voters approve a constitution which establishes a multi-party system.
Pascal Lissouba becomes president in Congo's first democratic election.
Civil strife
1993 - Bloody fighting between government and opposition forces over disputed parliamentary elections.
1994-95 - Ceasefire between government and opposition established; opposition given government posts.
1997 - Full-scale civil war breaks out; pro-Sassou Nguesso forces, aided by Angolan troops, capture Brazzaville, forcing Lissouba to flee.
1999 - Government and rebels sign a peace deal in Zambia providing for a national dialogue, demilitarisation of political parties and the re-admission of rebel units into the security forces.
2001 April - Peace conference ends by adopting a new constitution, paving the way for presidential and parliamentary elections.
2001 September - Transitional parliament adopts a draft constitution. Some 15,000 militia disarm in a cash-for-weapons scheme. IMF starts clearing Congo's $4bn debt.
2001 December - Former president, Pascal Lissouba, convicted in absentia on treason and corruption charges, and sentenced to 30 years' hard labour by the high court in Brazzaville.
2002 January - About 80% of voters in constitutional referendum approve amendments aimed at consolidating presidential powers.
2002 March - Denis Sassou Nguesso wins presidential elections unopposed after his main rivals are barred from the contest.
Clashes with rebels
2002 March - Intense fighting between government and "Ninja" rebels drives many thousands of civilians from their homes in Pool region. The rebels, loyal to former PM Bernard Kolelas and led by renegade priest Pastor Ntumi, name themselves after the famous Japanese warriors.
2002 June - Government troops battle Ninja rebels in Brazzaville. About 100 people are killed.
2003 March - Government signs deals with Ninja rebels aimed at ending fighting in Pool region. Ninja leader Pastor Ntumi agrees to end hostilities and allow the return of the rule of law.
2004 June - World diamond trade watchdog removes Congo from list of countries recognised as dealing legitimately in diamonds.
2005 April - Government says a group of army officers, arrested in January over an arms theft, had been planning a coup.
2005 October - Former PM Bernard Kolelas is allowed home to bury his wife after eight years in exile, during which time he was sentenced to death on war crimes charges. He is given an amnesty in November.
2006 January - Congo is chosen to lead the African Union in 2006 after disagreements within the body about Sudan's leadership bid.
President Sassou Nguesso accuses France of interfering in his country's affairs, following a decision by a French Appeal court to reopen an investigation into the disappearance of more than 350 refugees in 1999.
2007 June - Former "Ninja" rebels led by renegade Pastor Frederic Ntumi ceremoniously burn their weapons to demonstrate their commitment to peace.
2007 June-August - Parliamentary elections, boycotted by some 40 parties. Ruling party wins 90 percent of seats.
2007 November - London Club of private sector creditors cancels 80 percent of Congo's debt.
2009 May - French magistrate opens probe into alleged embezzlement by President Sassou Nguesso and two other African leaders following lawsuit by an anti-corruption group.
2009 July - President Denis Sassou Nguesso gains another seven years in power following elections boycotted by the opposition.
2010 March - Paris Club of creditor countries and Brazil agree to cancel all the debt owed to them by Congo - about $2.4 billion.
2010 August - Congo marks 50 years of independence from France.
2010 November - Polio epidemic kills 100.
French appeal court gives go-ahead for probe into corruption charges against three African leaders, including President Denis Sassou Nguesso.
