BOGOTA (Reuters) - Former Marxist FARC rebel commanders in Colombia, headed by their leader Rodrigo Londono, appeared before a tribunal on Friday that will try crimes allegedly committed during the country’s five-decade civil war.

Pablo Catatumbo, member of the FARC political party, arrives to attend a hearing of the Special Jurisdiction for Peace (JEP) tribunal in Bogota, Colombia, July 13, 2018. REUTERS/Luisa Gonzalez

The Special Jurisdiction for Peace (JEP) tribunal, founded under a 2016 peace deal between the government and Revolutionary Armed Forces of Colombia (FARC), will try cases considered representative of the war’s violence. The cases are based on investigations by authorities and accusations from victims.

The JEP, which is set to run for at least 15 years, aims to heal wounds left by the conflict and allow victims to hear the truth about loved ones as well as receive compensation from the FARC, including stolen land and property.

Three members of the FARC’s ruling secretariat attended the first hearing on Friday - Londono, known by his war alias Timochenko, Pablo Catatumbo, and Carlos Lozada. A fourth FARC leader, Jesus Santrich, joined via video conference from prison.

The hearing was a “historic event that constitutes a fundamental step in the efforts to put an end to an armed conflict,” said tribunal magistrate Julieta Lemaitre on the livestreamed session.

Some 7,000 FARC fighters demobilized last year and more than 4,600 of them have already submitted testimony for the JEP under the peace deal, negotiated in the Cuban capital Havana.

“I am here at your disposal, deeply emotional to see how that dream that we wove in Havana is crystallized,” said Londono, who was the FARC’s top commander and now chairs its political party.

The rest of the 31 FARC commanders summoned to the hearing did not attend and were represented by their lawyers.

“The country will never be the same again,” Colombia’s High Commissioner for Peace, Rodrigo Rivera, said in a statement. “The leaders of the FARC before the special tribunal is something that seemed impossible for 50 years.”

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The former rebel leaders are required by the tribunal to provide details on alleged kidnappings and forced disappearances between 1993 and 2012.

Ransom was one of the rebels’ main sources of financing, along with drug trafficking and extortion. The group earned more than $1.25 billion in ransoms from 8,100 kidnappings during those years, according to the attorney general’s office.

Families of victims say they hope the tribunal will bring to light where the remains of some of those who were kidnapped and murdered can be found.

“This shows that the FARC is fulfilling its promise and that they are willing to confess to the victims,” said Yolanda Pinto, head of the government’s Victims Unit, which helps those affected by the war and ensures they receive compensation.

“I feel satisfied that this will help heal,” said Pinto, whose husband was kidnapped and killed by the FARC in 2003.

Members of the armed forces who have been accused of being involved in human rights violations will also be summoned to appear before the JEP. Nearly 1,800 have submitted testimony.

The FARC began as an insurgency in 1964, fighting for better conditions for the rural poor. More than 220,000 people were killed in a conflict that saw rebels battle the army, right-wing paramilitaries and drug traffickers.

Those convicted by the tribunal of crimes including killings, sexual violence, kidnappings, and bombings, may be ordered to complete five-to-eight-year sentences of restorative work like rebuilding roads or schools.

Ex-fighters who are found by investigators to have lied or do not tell the whole truth but are convicted could receive harsher sentences of between five and 20 years in regular prisons.

President-elect Ivan Duque, who is due to replace President Juan Manuel Santos on Aug. 7, campaigned on seeking tougher sentences for FARC leaders and has said he would make adjustments to the agreements.

He said during the campaign that he was angry that ex-rebels will receive 10 seats in Congress before serving sentences for any crimes. Their five representatives in each house are due to be sworn in on July 20.