Ex-Bosnian Serb army head Ratko Mladic has made his first appearance at The Hague war crimes tribunal, but said he would not enter a plea to the "monstrous" and "obnoxious" charges.
He is charged with crimes in the 1992-95 Bosnian war, including the massacre of about 7,500 people in Srebrenica.
Gen Mladic told the court he had been "defending my people and my country".
He also said he was "gravely ill", but a court spokeswoman said health checks had shown he was fit to stand trial.
Nerma Jelacic said a variety of tests had been done on Gen Mladic since he arrived at The Hague, but none had turned up any health issues to cause concern.
Gen Mladic, who was arrested last week in Serbia, is charged with genocide, persecution, extermination, murder, deportation, inhumane acts, terror, deportation and hostage-taking, according to the tribunal indictment.
Prosecutors say this was his part in a plot to achieve the "elimination or permanent removal" of Muslims from large parts of Bosnia in pursuit of a Greater Serbia.
In his first hearing before the International Tribunal for the former Yugoslavia, Gen Mladic, 69, was asked if he could understand the proceedings and he confirmed that he could.
He gave his name and date of birth, although the date was different from the court records.
Court-appointed Serbian lawyer Aleksandar Aleksic represented Gen Mladic at the hearing. Gen Mladic may choose a permanent counsel for the trial later, or opt to conduct his own defence.
Judge Alphons Orie said the purpose of the hearing was to list the charges against Gen Mladic and ask him for a plea.
Gen Mladic's rights were read out in court, but he said: "I am a gravely ill man and need more time to understand what was read out, so please be patient."
The judge then asked if Gen Mladic had read and understood the indictment against him.
Gen Mladic said he needed at least two months to read the three binders of documents that had been brought to him.
However, Mr Aleksic said he believed his client had understood the indictment.
Gen Mladic then told the judge: "I do not want a single letter or sentence of that indictment to be read out to me."
However, the judge proceeded to read out a summary of the charges.
At some points, Gen Mladic shook his head.
When asked to enter a plea, he said the charges were "monstrous" and he needed more than a month to respond.
If Gen Mladic does not enter a plea within 30 days, the judges will enter pleas of not guilty on his behalf.
After a brief recess, the hearing moved into private session so Gen Mladic could express concerns about his health.
Then as the hearing ended, Gen Mladic said: "I defended my people, my country... now I am defending myself. I just have to say that I want to live to see that I am a free man."
He added: "I don't want to be helped to walk as if I were some blind cripple. If I want help, I'll ask for it."
BBC world affairs editor John Simpson, in the courtroom, said Gen Mladic had looked over at him and given a mocking salute.
At one point, one of the Srebrenica widows had caught Gen Mladic's eye and made a throat-cutting gesture, to which he smiled, adds our correspondent.
A new hearing was set for 4 July.
Relatives of some of the victims of the war gathered outside the courtroom awaiting Gen Mladic's arrival.
Munira Subasic, whose son and husband died in Srebrenica, told Reuters: "In 1995 I begged him to let my son go. He listened to me and promised to let him go. I trusted him at that moment.
"Sixteen years later, I am still searching for my son's bones."
Gen Mladic had earlier been examined by doctors in the medical facility of the detention unit at The Hague after arriving on Tuesday night.
On Thursday, Mr Aleksic said of his client: "He has not had proper healthcare for years and his condition is not good."
Also on Thursday, Mr Saljic said Gen Mladic had been treated for cancer two years ago at a Belgrade hospital.
Mr Saljic has previously been quoted as saying by Serbian media that his client had suffered three strokes and two heart attacks, was too ill to be sent to The Hague and would not live to the end of a trial.
One lawyer representing victims, Axel Hageldoorn, told Associated Press there was concern that "he is too sick to follow the trial to its end and there will be no verdict".
As well as Srebrenica, Europe's worst atrocity since World War II, Gen Mladic is also charged over the 44-month siege of the capital Sarajevo from May 1992 in which 10,000 people died.
Former Serbian President Slobodan Milosevic died of a heart attack at The Hague in 2006, four years into his own genocide trial.