Autodefensas Unidas de Colombia (AUC), commonly known as the "paramilitaries."

AUC paramilitaries have had a strong presence in the northern Colombian departments of Antioquia, Cordoba, Sucre and Bolivar, though they also have operated in other northern and southwestern Colombian states.

AUC was formed to fight the leftist FARC and ELN rebel groups.

Estimates of AUC strength have ranged from 7,000 to 30,000 paramilitaries, including former rebel and military personnel. All members of the AUC officially disarmed by April 2006, though an unknown number of former members are still believed to be active.

None.  

AUC has been accused of committing atrocities against Colombia's civilian population.

Its paramilitary targets have included the supporters of left-wing groups, including political activists, security officials and judges.

The AUC has also been accused of the massacres of entire villages. By forcing the residents out of their homes, the AUC occasionally gained control over narcotics-producing territories.

AUC paramilitaries have been known to assassinate suspected leftist supporters and engage left-wing guerrillas in direct combat.

The AUC adopted a cease-fire in December 2002, and some of its paramilitaries began laying down their arms in late 2003. By mid-2006, all official AUC blocs had formally disarmed.

The AUC was established as an umbrella organization to oppose leftist insurgents. The roots of the AUC can be traced back to the regional self-defense groups of the 1950s. Wealthy landowners commissioned local militia to protect their land and business interests from leftist groups. The militias grew in the 1980s with extensive funding from the drug cartels. The Medellin and Cali cartels funded militias to protect their coca and poppy fields from guerrillas trying to levy "taxes" on the illegal drug trade.

Two brothers, Fidel and Carlos Castano, established a powerful paramilitary group in the late 1980s in the north, the Autodefensas Campesinas de Codoba y Uruba (ACCU). The ACCU later allied itself with the urban death squad MAS (Death to Kidnappers) that was established by the drug cartels to protect their interests in the cities.

During the 1980s, the Colombian military supplied weapons and training to the right-wing militias to help fight leftist guerrillas. The government outlawed the militias in 1989, as reports of their atrocities grew.

Fidel Castano died under mysterious circumstances in the 1990s, and his brother Carlos assumed military command over the ACCU. Carlos embarked on a campaign to turn the ACCU into a national coordinating body for Colombia's right-wing paramilitary groups. In 1997, he founded the AUC. The ACCU was considered the most powerful group within the AUC.

Until recently, the AUC was considered to be the fastest-growing Colombian armed group. Many of its members were former soldiers and police officers. The Colombian Dept. of Justice estimated that at least 1,000 former soldiers and police officers joined the AUC after being sacked for human-rights abuses. Other members of the AUC included members of vigilante groups and smaller rural militias.

AUC's popularity stemmed from the fact that it provided security to those living in sparsely populated rural regions where government forces were few in number.

AUC was organized into several semi-independent blocs (bloques). Each bloc combined political, military and social functions. Some blocs were further subdivided into smaller fronts (frentes). The ACCU consisted of almost a dozen frentes, each commanded by a comandante. A central command had overall operational responsibility for the AUC.

As of the summer of 2003, the AUC listed its groups and their leaders as:

By 2008, the combined efforts of the Colombian and U.S. governments had blunted terrorist activities in Colombia. Government cooperation, especially involving prosecution of militant operatives in both countries, proved effective. The AUC, which took several years to demobilize under Colombia's repatriation program, is largely inoperative.

Some group remnants have also been engaged in illegal drug activities. A U.S. government report on human-rights in Colombia said the new groups "lacked the organization, reach and military capacity of the former AUC." While the AUC demobilization reduced killings and human-rights abuses, former AUC operatives have still engaged in such practices, often directed at government officials, journalists and trade unionists.

The United Nations has also expressed concerns about the re-constitution of former AUC operatives.

Fidel and Carlos Castano created the Autdefensas Campesinas de Cordoba y Uruba (ACCU) in northern Colombia to avenge the murders of their father and family by FARC guerrillas.

July: The AUC advanced on the National Liberation Army (ELN) stronghold in Serrania de San Lucas in Bolivar province. Some 4,000 peasants were displaced by the fighting.

November 11: Colombian troops engaged AUC fighters in San Martin, Colombia, and killed four paramilitaries.

December: Groups under the influence of AUC declared a cease-fire.

July: The Colombian government agreed to formal peace talks with the AUC.

Sept. 12: The U.S. State Dept. redesignated AUC as a terrorist group.

Nov. 25: The Cacique Nutibara faction of the AUC surrendered its weapons as part of a peace agreement with the government. The 800-strong group is based in the northwest city of Medellin.

Nov. 2: The government threatened to resume attacks against the AUC unless it continued disarmament.

Nov. 16: The AUC and Bogota agreed to continue demobilizations and to extend the deadline from Dec. 31, 2005, to a later date. By this time, around half of the AUC fighters had demobilized.

Dec. 12: Almost 2,000 members of the Central Bolivar faction of the AUC officially stood down and handed over their weapons.

April 12: Some 1,700 AUC fighters turned in their weapons in the town of Casibare. The action marked the final scheduled disarmament ceremony in the demobilization effort.

Aug 15: Colombia's last major paramilitary chief disarmed as part of a peace agreement with the government. Fredy "The German" Rendon, leader of the Elmer Cardenas bloc of the AUC, and 745 of his fighters surrendered their weapons in a ceremony in the Choco region.

Aug 16: Colombian authorities arrested 14 top AUC leaders, some of whom turned themselves in voluntarily. The government said the paramilitaries were not complying with the terms of an agreement that included amnesty.

Sept. 5: The remains of Carlos Castano were discovered and confirmed by DNA samples. It appeared that he was assassinated in 2004. The police were led to the site by a man who claimed to be the assassin. The hit was allegedly ordered by other paramilitary leaders.

September: Two AUC leaders, Alvaro Antonio Padilla and Fredy Castillo, were extradited to the U.S. to face drug-trafficking charges. The extradition of five other leaders was also authorized.

November: The Colombian Supreme Court opened an investigation into six federal legislators because of their alleged connections to the AUC. Three other legislators were arrested earlier in the month on similar charges.

December: The remaining AUC groups pulled out of peace negotiations with the government. The withdrawal was triggered by the government’s transfer of 59 AUC leaders to a high-security prison.

Mar. 14: In the U.S., the Chiquita Brands banana company was fined $25 million for paying the AUC $1.7 million for protection between 1997 and 2004.

Mar. 26: A CIA report alleged that Colombian army chief Gen. Mario Montoya had connections with the AUC. The Colombian government denied the accusation.

May: Five additional Colombian legislators were charged with having connections to the AUC.

December: Evidence surfaced indicating that some demobilized AUC fighters had rearmed.

May: In two separate actions, Colombia extradited a total of 15 former AUC paramilitary leaders to the U.S. Charges included illicit drug-trafficking, money-laundering and material support of terrorism. The U.S. also contended that the AUC operatives had failed to comply with their Justice and Peace Law (JPL) obligations in Colombia. Several continued to testify from the United States in hopes of receiving reduced penalties in Colombia after completing their U.S. sentences.

June 17: The U.S. Justice Dept. announced that Diego Fernando Murillo-Bejarano ("Don Berna"), the top leader of the AUC, entered a guilty plea in U.S. District Court for conspiring to import cocaine into the United States. The indictment noted that AUC was engaged in warfare with Colombia's FARC and also involved in narcotics-trafficking to support its terrorist activities. The extradition and guilty plea of Diego Murillo-Bejarano represented a "monumental defeat to the leadership of the AUC," according to a U.S. official.

Feb. 27: Chiquita Brands International asked a U.S. federal court to dismiss claims related to payments the company made to AUC. Parties filing the lawsuit sought "wrongful death" claims against the company, contending that the payments supported AUC’s killing relatives of the claimants. The company conceded that it made the payments, which it characterized as extortion, but said it was not responsible for the deaths. 

April 22: The U.S. Justice Dept. issued an indictment charging Colombian Daniel Rendon-Herrera ("Don Mario") with conspiring to provide material support to a foreign terrorist organization (i.e., the AUC) and to import cocaine into the United States. Rendon-Herrera was captured by Colombian authorities on April 15 and remained in Colombian custody at the time of the indictment.

June 6: Authorities in Bogota opened the a trial of Salvatore Mancuso, former head of AUC. While Mancuso remained in custody in the U.S., Colombian officials began their proceedings against Mancuso, who was charged with more than 112 crimes, including massacres, forced displacement and participating in the killing of unionists.

June 24: Former AUC leader Diego Jose Martinez died in prison in Colombia. While the cited cause of death was a heart attack, officials reportedly did not rule out the possibility that Martinez was poisoned. Martinez, 35, had been the leader of AUC's Toloma Bloc. Martinez was said to have demobilized in 2005.