1819: Independence forces of Simón Bolívar defeat Spanish army to set up the Republic of Gran Colombia with Ecuador, Panama, Venezuela, as well as Colombia.
1948: The assassination of the left-wing Mayor of Bogota, Jorge Eliécer Gaitán, leads to the 'Bogotazo', massive urban riots and, subsequently, to a period of civil strife known as 'La Violencia' that lasts until 1957. An estimated 250,000-300,000 are killed.
1958-1978: Top level political agreement to establish a 'National Front', whereby all government offices are shared between Liberals and Conservatives. Other political parties are banned.
1964-1966: The Revolutionary Armed Forces of Colombia (FARC) is founded, and goes on to be leading guerrilla threat to the Colombian state.
1964: Leftist National Liberation Army (ELN) and Maoist People’s Liberation Army (EPL) is formed.
1970: Formation of left-wing M-19 guerrilla group.
1978: Intense campaign against drug traffickers by President Julio César Turbay Ayala (Liberal).
1982-1985: President Belisario Betancur (Conservative) negotiates a cease-fire, grants amnesties to guerrillas and releases political prisoners. Negotiations fall apart when the armed M-19 guerrillas briefly seize the Justice Court in Bogota. Over 100 people die as the army move to retake the building, including 11 Supreme Court judges and several of the leading members of the M-19. The M-19 was subsequently much weakened.
1985: The FARC and the Colombian Communist Party found the Patriotic Union Party (UP), as part of the peace negotiation process between Betancur and the guerrillas. Since September 2002 the UP has had no legal representatives.
1986-1990: President Virgilio Barco Vargas (Liberal) continues the peace process but the period is marked by extreme violence, including from increasingly powerful drug cartels and paramilitary groups.
1989: M-19 becomes a legal political party (M-19 Democratic Alliance) following a peace agreement with the government.
1990: Three presidential candidates are assassinated by narco-terrorists. President César Gaviria Trujillo (Liberal) is elected on anti-drug platform.
1991: New Colombian Constitution. It replaces the 1886 constitution and bans the extradition of Colombian citizens (this article was repealed in 1996), includes new human rights and for indigenous groups, and reforms Colombia’s political institutions.
1993: Medellin drug-cartel leader Pablo Escobar is killed by Colombian security forces. Indiscriminate acts of violence follow.
1997: The United Self-Defence Forces of Colombia (AUC) is established, an umbrella organisation of right-wing paramilitary groupings.
1998-2002: President Andrés Pastrana Arango (Conservative) initiates peace talks with guerrillas. After three years of convoluted talks, they end after the guerrilla kidnaps a congressman and other political figures.
2000: Pastrana launches controversial and unpopular Plan Colombia, with the aid of the USA, to put to a halt the flow of cocaine and heroine entering the USA over the Mexican border and to fight drug trafficking and rebels that benefit form the trade.
2001: The USA State Department adds the AUC to the list of Foreign Terrorist Organizations.
2002: Independent candidate Álvaro Uribe Vélez wins presidential elections.
2003-2006: Demobilisation of the AUC.
2004: Uribe launches 'Plan Patriota', which is widely seen as a continuation of Pastrana’s Plan Colombia, and also controversial. With the financial support of the USA, it aims to uproot guerrilla groups in Colombia, gain military presence in remote areas of the country, traditionally controlled by the guerrillas, and introduce social programmes.
2005: Uribe sets the Justice and Peace Law that reduces punishments for guerrilla and paramilitary members if they surrender their arms, renounce violence and return illegal assets.
2006: The FARC launches 'Plan Resistencia', a final offensive to counteract military activities and, in view of the 2006 presidential elections, undermine the public’s perception that the security situation has improved under Uribe’s government.
2006: Uribe’s second presidential election win, after a presidential re-election ban is revoked.
2006: Preliminary peace talks between the government and the ELN take place in Cuba. Formal negotiations are yet to start however.
2007: Connections between paramilitary groups and several congressmen come to light, creating the parapolitics scandal.
2008: Diplomatic crisis between Colombia, Ecuador and Venezuela intensifies following a Colombian cross-border strike into Ecuador. FARC leader Raúl Reyes is killed.
2008: Manuel Marulanda Velez, known as 'Tirofijo' and main leader of FARC-EP, dies of a heart attack.
2008: Release of Ingrid Betancourt, a high-profile FARC hostage, after over six years in captivity.
2008: 'False Positives' scandal, in which the government and army is accused of colluding in the murder of up to 1,500 civilians who were then presented as guerrillas killed in combat.
2009: The FARC launches 'Plan Rebirth' to avoid defeat by intensifying guerrilla warfare – i.e. use of landmines, snipers and bomb attacks in urban areas. This plan is counteracted by 'Strategic Leap', a military offensive in areas where guerrillas still have a strong military presence.
2009: Colombia and US sign Military Cooperation Agreement.
2010: Juan Manuel Santos, a former Defence Minister under Uribe, is elected President.
2011: Oliver Solarte and Jerónimo Galeano killed by army - both high level FARC members, while FARC continues taking hostages.