A German court in the northeastern state of Brandenburg on Tuesday sentenced a former concentration camp guard to five years in jail.
Prosecutors accused the pensioner of involvement in the murders of 3,518 prisoners at the Sachsenhausen camp between 1942 and 1945.
At the age of 101, he is the oldest person to have ever faced trial over Nazi crimes during World War II, and to be found guilty.
"In your role, you willingly supported the mass extermination," presiding judge Udo Lechtermann told the accused.
The defendant, who now lives in Brandenburg state, had pleaded innocent throughout the trial. He did so again on Monday, just ahead of Tuesday's verdict.
Under cross-examination, the defendant denied knowledge of the vast crimes that took place at Sachsenhausen, saying he had been a farm laborer at the time in question.
Prosecutors maintained that he "knowingly and willingly" took part in crimes as a guard at the camp. They produced documents for a guard with the same name, date of birth, and birthplace as the man, as well as other papers.
The prosecutors had called for the defendant to be punished with five years in prison.
What were the allegations?
The allegations included participating in "execution by firing squad of Soviet prisoners of war in 1942" and the deployment of "poisonous gas Zyklon B" in the Sachsenhausen concentration camp's gas chambers.
He has been on trial since October at the Neuruppin regional court. Hearings in the case have been held in the nearby eastern city of Brandenburg, near the man's home.
He has remained free for the duration of his trial. It was considered highly unlikely he would be jailed given his age.
What happened at Sachsenhausen?
Over 200,000 people — mostly Jewish but also members of the Roma community, regime opponents, and gay people — were imprisoned at Sachsenhausen between 1936 and 1945 for no reason other than their religious and ethnic identity, sexuality, or political beliefs.
Tens of thousands died from forced labor or as the result of unethical medical experiments, hunger, and disease, in addition to the acts of mass murder that took place there. Six million Jewish people were murdered during the Holocaust.
Soviet troops arrived first to liberate the camp north of Berlin in the town of Oranienburg in 1945.