The Khmer Rouge's former head of state, Khieu Samphan, 87, and "Brother Number 2" Nuon Chea, 92, are the two most senior living members of the ultra-Maoist group that seized control of Cambodia from 1975-1979.
The end of 2011 is marked by memorable testimony by the two defendants.
Cambodian Buddhist monks wait in line to enter into the courtroom before the hearings against two former Khmer Rouge senior leaders, at the United Nations -backed war crimes tribunal on the outskirts of Phnom Penh, Cambodia, on November 16, 2018.
Khieu Samphan had at one point been the smiling, polite figurehead who nominally was the head of state in the Khmer Rouge regime.
Many believe the decision will be the last for the tribunal, which has been marred by allegations of political interference.
There had been debate for years among legal experts at to whether the killings by the Khmer Rouge constituted genocide, as by far the majority of their victims were fellow Cambodians.
Just talking about the Khmer Rouge brought back frightful memories of life in those years, he said.
The court, a hybrid UN-Cambodian tribunal, was set up in 2005 to bring to justice "those most responsible" for the deaths under the Khmer Rouge, has convicted just three people.
The Khmer Rouge wanted to transform Cambodia into a rural, classless society.
Prime Minister Hun Sen - himself a former Khmer Rouge cadre - has repeatedly warned he would not allow more investigations to proceed, citing vague threats to stability.
Initial work had been done on two more cases involving four middle-ranking members of the Khmer Rouge, but they have been scuttled or bottled up by the tribunal, which is a hybrid court in which Cambodian prosecutors and judges are paired with worldwide counterparts.
But many Cambodians pay little attention to the tribunal, and young people in particular are keen for their country to be known for something other than the "Killing Fields". He was able to trade on his reputation as an honest left-wing academic and lawmaker in 1960s Cambodia before repression drove him underground and into the jungle with the then-nascent Khmer Rouge movement.
Although Chea and Samphan have suggested in the past that they are victims of a political vendetta, in 2013, they acknowledged a degree of responsibility for the atrocities committed in their names.
Khieu Samphan described the claim of genocide as "Vietnamese propaganda", a defence he and other former Khmer Rouge leaders have made previously.
Both Khieu Samphan and Nuon Chea appeared for the court session but Nuon Chea left after about 40 minutes because of back pain, the court was told.
Cambodians have always been suspicious of Vietnam, their much bigger eastern neighbour, and prejudice against Vietnamese is widespread. The U.S. heavily bombed the Cambodian countryside during the 1970-75 civil war that led to the Khmer Rouge's seizure of power. "Last night, I could not sleep because I was afraid that Nuon Chea and Khieu Samphan could die before this verdict was announced".