DAKAR, Senegal — Hissène Habré, the former president of Chad, was sentenced to life in prison after he was found guilty of crimes against humanity, torture and sex crimes on Monday, more than 20 years after the start of a campaign to hold him accountable for the suffering and death of tens of thousands of people.
Mr. Habré, who ruled Chad from 1982 to 1990, when he was deposed by the current president, Idriss Déby, stood trial before a special court in Senegal created to handle the case. Prosecutors had sought a life sentence, which he is expected to serve in Senegal.
“The systematic torture at such a large scale was his way of governing,” said Gberdao Gustave Kam, the presiding judge, who read a summary of the verdict. “Hissène Habré showed no compassion toward the victims or any regret about the massacres and rapes that were committed.”
Victims and relatives of victims screamed with joy after the verdict was announced. Mr. Habré, who had sat silently during the 90-minute hearing, raised his fists to supporters and shouted for several minutes until he was led away by armed guards.
The fact that the trial even took place was considered a victory for many of the victims of Mr. Habré’s government, who fought for more than two decades to bring him to justice.
The case meandered through the judiciary in Belgium and elsewhere for years before landing in Senegal, where Mr. Habré fled after being forced from power.
On Monday morning, a group of about 30 victims and widows of victims slowly walked into the courthouse together, many graying and using canes, a testament to the time it had taken for the case to come to trial.
“This is a testimony to the perseverance of a band of victims, activists and supporters who made this trial happen,” said Reed Brody, a Human Rights Watch lawyer from New York who was influential in pursuing the case. “This trial was the result of the sweat and determination of the survivors.”
Several international human rights lawyers were in the gallery on Monday to hear the verdict, including the prosecutor who indicted Augusto Pinochet, the dictator who ruled Chile from 1973 to 1990. Mr. Habré has been called the “African Pinochet.”
During the trial, which started in July, prosecutors presented secret-police archives that recorded the names of 12,321 prisoners, interrogation reports and information about the deaths in detention of more than 1,200 people.
François Serres, Mr. Habré’s lawyer, has dismissed the records as “fakes.”
During the trial, defense attorneys said there was no evidence connecting Mr. Habré to crimes committed by others and contended that the prosecution was political. Mr. Habré’s son and other relatives were in court on Monday but declined to comment before the proceedings.
According to a Chadian truth commission, Mr. Habré’s government killed more than 40,000 people who were believed to be enemies of the state, or who had merely come under suspicion.
Evidence heard by the court, known as the Extraordinary African Chambers, included tales of torture and putrid conditions in prisons where Mr. Habré’s enemies were taken, sometimes without being given any reason for their detention.
Testimony involving sex crimes also figured in the trial. One woman described Mr. Habré raping her, insisting when a judge interrupted that she be allowed to continue her testimony in public so that the world could know what the former president had done.
On Monday, the judges specifically convicted Mr. Habré of that rape.
Others testified about relatives who had disappeared, and former prisoners described being wounded after their limbs were tied behind their backs.
One former prisoner, Clément Abaifouta, said in an interview that he could never forget the horrors he had seen in jail.
Mr. Abaifouta, who was in court for the verdict, had worked in a prison kitchen and a laundry room before he was ordered to take on a new role, as gravedigger.
“What broke my life is the fact that I buried about 1,000 people,” he said. “With all that Habré did, we could cut him into pieces and it wouldn’t satisfy everyone.”
Mr. Habré was first indicted in 2000. The setting of the trial in Senegal offered a peculiarity: the courts of one country prosecuting the former leader of another in a human rights case.
The trial proceeded with the blessing of the African Union, even though the organization has long complained that Africans are often singled out before the International Criminal Court in The Hague.
The Hague court had no jurisdiction in this case because its authority is limited to events that took place after it was fully established in 2002. That restriction prompted the African Union to intervene.
The three-judge panel, with two judges from Senegal and one from Burkina Faso, used Senegalese law to reach the verdict.
Mr. Habré took power during a coup that was covertly aided by the United States, and he also received weapons and assistance from France, Israel and the United States to keep Libya, to the north of Chad, and Col. Muammar el-Qaddafi, then the Libyan leader, at bay.
At the beginning of the case, Mr. Habré was a combative defendant, brought into court by force after refusing to participate in the hearings. Some of his supporters started a website denouncing the trial and his treatment by the court.
Mr. Habré often wore sunglasses and a turban during testimony, rarely turning to look at the more than 90 witnesses, according to courtroom observers. He dressed in a similar fashion on Monday, looking more like a nomad facing a sandstorm than a former president on trial.
Suleyman Guengueng, a political prisoner during the Habré years who documented the abuses he saw while in detention, was in the courtroom on Monday to hear the verdict and said he hoped the trial would send a message to dictators around the world, as well as to their victims.
“To all the dictators violating human rights in the world, this can happen,” Mr. Guengueng said. “To all their victims, don’t shut your mouth, open your mouth.”