Ex-dictator Efrain Rios Montt was found guilty of genocide and war crimes stemming from massacres of indigenous people during Guatemala's long civil war.
Rios Montt thus became the first former Latin American dictator convicted of trying to exterminate an entire group of people, in a brief but particularly gruesome stretch of a war that started in 1960, dragged on for 36 years and left around 200,000 people dead or missing.
The 86-year-old was sentenced to 80 years in prison, although he vowed to appeal. He got 50 years for genocide and 30 years for war crimes.
"The defendant is responsible for masterminding the crime of genocide," Judge Jazmin Barrios said. "The corresponding punishment must be imposed."
She said he was also guilty of war crimes. The court, filled with victims and their relatives, erupted in applause and cheers. Other Latin American countries such as Chile, Brazil and Argentina were also ruled by cruel military despots in the 1970s and '80s, and some leaders and officers have been convicted for abuses. But this was the first time an outright genocide conviction was handed down in the region.
Activists say the verdict was also historic because it marked the first time that a court has found one of its country's citizens guilty of genocide. Other genocide convictions, like those stemming from Rwanda's orgy of ethnic violence in 1994, were handed down by international courts.
The aged retired general remained stony-faced as the verdict was read. When the judge said his house arrest was being revoked and he would be sent to jail, he nodded. Later, he insisted that his conscience was clear as he derided the verdict.