Key developments in the half-century of hostilities between Colombia's government and the country's largest rebel movement:
—May 1964: Rebel leader Manuel Marulanda, alias "Tirofijo," founds Revolutionary Armed Forces of Colombia, known as FARC.
—Aug. 7, 1982: Government of President Belisario Betancur starts peace negotiations with FARC.
—June 1987: Tenuous-at-best cease-fire wounded when rebels attack kills 25 soldiers in southern Colombia.
—April 1991: FARC, along with fellow rebel groups National Liberation Army and Popular Liberation Army, sit down for talks with government delegates in Venezuela. Talks are later moved to Mexico.
—October 1992: Negotiations end with no agreement.
—August 1998: President Andres Pastrana announces new peace effort with FARC. Sets up Switzerland-sized demilitarized zone in southern Colombia where talks can be held.
—Feb. 20, 2002: Rebels hijack plane and take captive a senator who is member of peace commission. Pastrana breaks off negotiations and orders security forces to return to the demilitarized zone.
—December 2004: Undercover Colombian agents capture Rodrigo Granda, considered FARC's "foreign minister," in Venezuela and move him to Colombia.
—Aug. 16, 2007: Venezuelan President Hugo Chavez offers to mediate between FARC and Colombian President Alvaro Uribe. Effort collapses few months later.
—March 1, 2008: FARC Secretariat member known by alias Raul Reyes killed in Colombian air attack on his clandestine guerrilla camp in neighboring Ecuador.
—March 26, 2008: Top FARC leader Marulanda dies of natural causes after more than four decades fighting government.
—Sept. 22, 2010: No. 2 FARC commander and top military strategist Jorge Briceno, alias Mono Jojoy, killed by air strike.
—Nov. 4, 2011: Top FARC commander Gullermo Saenz, alias Alfonso Cano, killed in attack by military.
—Feb. 26, 2012: FARC renounces kidnapping for extortion and frees all military officers in captivity.
—Aug. 12, 2012: President Juan Manuel Santos announces new peace talks with FARC. They begin two months later in Oslo, Norway, and later move to Havana.
—Aug. 24, 2016: Santos' government and FARC announce peace accord.
—Sept. 23, 2016: FARC leaders pledge their unanimous support to the accord after a week of deliberations on a remote savannah in southern Colombia.
—Sept. 26, 2016: Santos and FARC's top commander formally sign accord before regional heads of state, U.N. secretary-general and U.S. secretary of state.
—Oct. 2, 2016: Colombian voters narrowly reject the accord.