The divisions in Colombia that have led to the ungovernable mess that is the country today began 150 years ago. In 1849, the colonial ruling class split into two formal political parties: federalist Liberals and centrist Conservatives. Following a prolonged series of regional battles, when both sides took up arms, a Liberal revolt in 1899 sparked the War of 1,000 Days. The country' first full-scale civil war left 100,000 dead, mainly from the rural working class, who were called upon to take sides. (In 1903, the US took advantage of Colombia's upheaval and backed a separatist movement in Panama, then a Colombian province, which led to the creation of an independent republic and allowed the US to construct the inter-ocean canal under its own rather than Colombian control.)

After a period of relative peace between the Liberals and Conservatives, the assassination in 1948 of the populist Liberal leader, Jorge Elicier Gaitan, sparked a period known simply as 'La Violencia'. Political leaders provided arms and ideology from the safety of the cities, while in the countryside party supporters massacred each other; this time the death toll reached 300,000. By 1953, elements among the Liberal faction began to take on a radical edge, and revolutionary guerrilla groups began to emerge. Among them, in the state of Tolima, was a band led by Manuel Marulanda Velez, today the veteran leader of the Revolutionary Armed Forces of Colombia (Farc).

The response of the warring parties was rapid and cynical. Together, Liberals and Conservatives backed a military coup in 1953 in an attempt to quell the revolutionary insurgents. Four years later, the two parties signed an agreement to form a 'National Front' and share power. From the beginning, the National Front shied away from agrarian reform. It opted instead for 'Operation Colombia' - the development of a powerful business sector in the countryside that actually called for the forced displacement of the rural population to the cities. The idea was that peasant farmers and their families would be incorporated into an urban construction boom, thus generating vigorous economic growth. At the same time, the state undertook large-scale military operations aimed at wiping out resistance among peasant communities and the Communist self-defence groups that were supporting them. The massive aerial bombardments of one region, Marquetalia, laid waste to an entire community. But it failed to kill one Manuel Marulanda, who fled to the southern jungles with other survivors to form Farc in 1962. A second rebel group, the National Liberation Army (ELN), appeared in 1966, inspired by the Cuban Revolution.

In response, right-wing self-defence groups - paramilitaries - were formed to protect landowners and assist the armed forces in repelling the increasingly powerful guerrillas and their civilian support. The conflict snowballed, thousands of civilians were slaughtered each year, but the state persistently pursued its drive for economic development.

Following peace overtures made by President Belisario Betancur in 1985, some guerrillas agreed to disarm and seek political representation. But, under the banner of the the Patriotic Union (UP), they were so successful that a manhunt began against them. Over 10 years, 3,000 UP members - including two presidential candidates and six congressional representatives - were assassinated before the rebels gave up politics as useless to their cause and returned to arms.

Until the mid-80s, it was still legal for the military and landowners to foster paramilitary armies, and as late as the early 90s the opening up of Colombia's economy to market forces was preceded by a massive state offensive against the Casa Verde or 'Green House' - Farc's headquarters in the southern jungles. But the rebels would not lie down and die. Indeed, Marulanda, who claims not to have set foot in a Colombian town during his entire 35 years as a rebel leader, has built Farc into a national fighting force of 20,000 men and women. The ELN have 5,000 under arms.

Ranged against them is the Autodefensas Unidas de Colombia (AUC), an illegal paramilitary army, known as the headcutters and run by the country's most feared warlord, Carlos Castano, that also numbers 5,000. The AUC is backed by major drug traffickers, landowners and hard-line members of the military and the political right. In recent years the AUC has roamed the Colombian countryside with impunity, massacring and torturing whole villages said to be supporting the guerrillas.

Operation Colombia succeeded in at least one of its aims: until very recently, Colombia's economy has been a regional star and the envy of Latin America, with decades of unbroken year-on-year growth. But the rural population - those who were not murdered for their resistance - were not included in the success story. Those who have clung on in the countryside live in abject poverty, and the vast majority of those displaced to the cities live in squalid misery, without work, income or essential services. Tens of thousands have been killed and more than a million displaced from their homes in the past five years alone.