A Guatemalan judge ordered former dictator Efrain Rios Montt to stand trial on charges of genocide for the slaughter of more than 1,750 native Maya people during his 1982-83 regime.
The retired general, now 86, sat stoically as Judge Miguel Galvez ordered the opening of a trial "for the crimes of genocide" and crimes against humanity.
The landmark decision marks the first time that genocide proceedings have been brought in the Central American country over the 36-year civil war that ended in 1996, leaving an estimated 200,000 people dead, according to the UN.
Outside the courthouse in Guatemala City, relatives of victims -- some wearing red carnations and clutching photographs of their loved ones -- lit firecrackers in celebration after the ruling was read out.
Rios Montt is accused of orchestrating the massacre of more than 1,750 indigenous Ixil Maya people in Quiche department during his time in power.
"There are serious bases on which to put him on oral and public trial for his alleged participation in the crimes attributed to him," Galvez said in a small courtroom packed with relatives of victims and rights activists.
Rios Montt is known for his "scorched earth" campaign against people the government claimed were leftist rebels, but who were often indigenous Maya community members not involved in the conflict.
Dressed in a gray suit, the former strongman arrived on time for the hearing. Upon his entry into the courtroom, a small group of retired soldiers stood at attention and saluted him.
Once the judge issued his ruling and ended the hearing, activists in the courtroom clapped and cheered, to the visible anger of retired soldiers.
Rights advocates have worked for years to see Rios Montt tried, but he avoided court action, at one point by getting elected to Guatemala's congress -- and thereby winning parliamentary immunity.
"We are beginning to see the light at the end of the tunnel of impunity that Guatemala has endured over the past decades," said activist Iduvina Hernandez.
Human Rights Watch called the decision to prosecute Rios Montt a "major step forward for accountability in Guatemala."
"The fact that a judge has ordered the trial of a former head of state is a remarkable development in a country where impunity for past atrocities has long been the norm," said the group's Americas director, Jose Miguel Vivanco.
Galvez also ruled that he would open a genocide trial against retired general Jose Rodriguez, a former member of the military leadership who arrived in court in a wheelchair.
The judge told Rios Montt and Rodriguez to appear at a hearing on January 31 for the presentation of evidence.
Until then, Rios Montt will remain under house arrest while Rodriguez will remain at a military hospital where he has been treated for a stroke his attorneys say he suffered in December.
Attorneys for Rios Montt, who came to power in a coup in March 1982 and ruled until August 1983, argued that he was never aware of the massacres committed by the army.
"They want to stick something to Rios Montt that he never did," said his lawyer, Danilo Rodriguez, who happens to be a former guerrilla.
Another attorney for Rios Montt, Francisco Palomo, told reporters the defense team would appeal Galvez's decision.
"We will be presenting an appeal. We are not afraid of facing a trial, as long as it is a fair one... not a lynch mob," said Palomo.
Outside the courthouse, a group of relatives of victims set up a makeshift altar, where they placed flowers and lit incense.
Indigenous Maya communities make up a majority of the population in rural Guatemala.