In 1963, students, Catholic radicals and left-wing intellectuals hoping to emulate Fidel Castro's communist revolution in Cuba founded ELN, Colombia's second-largest leftist insurgency army and FARC rival.

ELN, which operates mainly in northeastern Colombia, has about 4,000 members, although advances by AUC paramilitaries have damaged ELN's strength, size and support base. The Pastrana administration negotiated with ELN but denied its requests for the type of zone of control the government granted FARC.

ELN is known for kidnapping wealthy Colombians for ransom, bombing campaigns and extortion against multinational and domestic oil companies. ELN attacks on oil pipelines have killed civilians and drawn the attention of the U.S. government, which has suggested training the Colombian armed forces to protect oil facilities. It has also recently entered the drug trade.

ELN and the Colombian government began a round of talks mediated by Mexico in mid-2004. ELN withdrew from the talks after the Mexican government voted to condemn Cuba's human rights record at the United Nations in April 2005. One year later, the ELN began a second round of talks with the Colombian government hosted by Fidel Castro in Cuba. (The first round took place in Cuba in December 2005.) The sides did not reach agreement but promised to meet again in Cuba to try and hammer out an agenda for a formal peace process.

However, on March 2, 2006, ELN did call a truce for the March 12 legislative elections.

(from PBS.org series on Colombia http://www.pbs.org/independentlens/lasierra/rebels.html)