The death of Jorge Briceno, also known as Mono Jojoy, is a huge setback for the Revolutionary Armed Forces of Colombia, or FARC, which has been reeling from years of pressure by an increasingly effective U.S.-backed military.
President Juan Manuel Santos called the attack "the most crushing blow against the FARC in its entire history" - more important than the March 2008 bombing raid across the border with Ecuador that killed FARC foreign minister Raul Reyes or the bloodless ruse that July that freed former presidential candidate Ingrid Betancourt, three U.S. contractors and 11 other hostages.
Santos, who was defense minister during both operations, got the news while jogging in New York City's Central Park. He explained to The Associated Press what Briceno's death means to Colombians: "It is as if they told New Yorkers that Osama bin Laden had fallen."
Briceno, 57, joined the FARC as an illiterate teenager and spent the rest of his life in the jungle, becoming a feared and charismatic commander in a force that a decade ago controlled nearly half of Colombia. Analysts predicted his loss could lead many rebels to give up the fight and might nudge the FARC to seek peace in earnest.
Santos told reporters that at least 20 rebels were killed, including other senior insurgents whose identities were not disclosed pending fingerprint and DNA tests, in operations that began Monday night with bombing raids involving at least 30 warplanes and 27 helicopters and ended with ground combat on Wednesday.
Air force chief Gen. Julio Gonzalez told the AP that Super Tucano and other warplanes dropped more than 50 bombs on the camp.
Commandos found Briceno's body outside a concrete bunker in a camp laced with tunnels and recovered at least 14 laptop computers and 50 USB drives, officials said. They said the raid was six months in the making and benefitted from radio spectrum surveillance.
Defense Minister Rodrigo Rivera higlighted "the collaboration of members of the FARC itself" and added that "the FARC is rotting inside."
He did not offer specifics, though military officials said privately that they were discussing reward payments to collaborators.
An army general told the AP that a single FARC turncoat led military intelligence agents to Briceno and had been spirited out of the country. The general insisted on not being named because he was not authoritized to talk to reporters.
The U.S. State Department had offered a $5 million reward for Briceno. The biggest reward known to have been paid for fingering a FARC commander was $2.5 million to an informant who led authorities to Reyes' camp.
Briceno had been rotating for months among a series of camps in a rugged area of nearly 4,000 square miles (1 million-hectares) where the Andes mountains drop off into eastern plains that include La Macarena massif, a national park, said one senior government official.
Police and Navy intelligence agents succeeded in pinpointing his movements, said the official, who spoke on condition of anonymity due to the subject's sensitivity.
The area is the cradle of the FARC, which was co-founded in 1964 by Briceno's mentor Manuel Marulanda, a legendary fighter who died in 2008 of an apparent heart attack in the same region.
Briceno, whose walrus mustache made him widely recognizable, had risen through the insurgency's ranks to become its most powerful and respected field commander as well as a major drug trafficker.
His rise saw the rebels increasingly turn to cocaine production, evolving from taxing farmers who grew coca to producing the drug and selling it to exporters.
The first major attack on record ordered by Briceno was a 1987 ambush in San Vicente del Caguan that killed 26 soldiers and wounded 44. The biggest was the 1998 taking of the provincial capital of Mitu in which 60 police officers were killed and 30 captured.
"He was at the heart of the FARC's military effort and of its morale," said Sergio Jaramillo, Santos' national security adviser.
Military analyst Alfredo Rangel said Briceno's death could lead to many more desertions, including even front commanders. Former Interior Minister Fernando Londono said Briceno was the only "irreplaceable" FARC commander.
Rivera said Briceno was caught at "the mother of all FARC camps," a complex some 300 yards from end to end. He said troops engaged rebels in ground combat on Wednesday and were only able to confirm Briceno's death on Thursday morning. Rivera said five troops were wounded with the only government death an explosives-sniffing dog.
Briceno belonged to the FARC's seven-member ruling Secretariat. Like most insurgents from a humble background, he was a fighter for most of his life, joining as a youth and even learning how to read as a rebel.
The group's main leader, Alfonso Cano, remains at large and is believed to be in the mountains of central Colombia. Military commanders claim they've been closing the noose on him as well. Colombian officials say other Secretariat members are hiding out in neighboring Venezuela.
The hemisphere's last remaining large rebel army, whose numbers authorities estimate at about 8,000 - half its strength of a decade ago - the FARC has been badly weakened since 2002 by Washington's strongest ally in Latin America. Colombia has received more than $6 billion in U.S. aid, including Blackhawk helicopters and training by Green Berets.
Many Colombians believe Briceno was a key obstacle to efforts to renew peace talks.
Betancourt, who is on a book tour in New York promoting her memoir of FARC captivity, said in an interview with NPR on Thursday that Briceno was one of the rebels' "bloodiest commanders," adding that as long as he was alive she didn't think Colombia could have a serious peace process.
However, he was less rigidly dogmatic than Cano, a Bogota-bred intellectual.
Analyst Leon Valencia of the left-leaning think tank Nuevo Arco Iris said Briceno's death marked the end of the FARC's Eastern Bloc, which had been its strongest.
He said he expected the FARC would now seek to negotiate.
Santos has rejected a peace dialogue unless the FARC ends kidnapping and extortion and halts attacks that claimed the lives of more than 30 police officers since he took office Aug. 7.
"This is the 'Welcome Operation' that we have been promising the FARC," said Santos, who was elected on a promise to continue former President Alvaro Uribe's withering military campaign against the FARC. It comes less than a week after Colombia's military killed at least 22 FARC fighters in bombing a rebel camp near Ecuador.
U.S. Rep. Jim McGovern, a Massachusetts Democrat who follows Colombia closely, called on Cano to initiate a cease-fire and release all remaining hostages. An estimated 18 still fester in Colombian jungles.
"Now is the time to open genuine negotiations and bring this long conflict to an end," he said in a statement.
However critics say the root cause of Colombia's conflict - a still-widening gulf between its richest and poorest - remains to be seriously addressed.
Briceno, born Victor Julio Suarez Rojas in the town of Cabrera southeast of Bogota, became well-known internationally during failed 1999-2002 peace talks in a Switzerland-sized swath of southern Colombia that included the La Macarena region.
A swaggering figure with a wry sense of humor and easy laughter, a portly Briceno would hold court with reporters and top Colombian officials in a safe haven granted for those talks, arriving on rutted dirt roads in stolen late-model SUVs with a dozen or so female bodyguards.
Photographs of him more recently show a gaunt man who authorities say suffered from diabetes.
Rebel deserters have described him as tough, decisive and often cruel - a strict disciplinarian. One said he once ordered a female guerrilla who was seven months pregnant to abort.
The FARC increasingly turned to drug trafficking in the late 1990s, when it was at the height of its military power, as a means of financial support.