The former Bosnian Serb leader, who has been accused of the biggest mass murder in Europe since the second world war, denies two counts of genocide and nine other counts of murder, extermination, persecution, forced deportation and the seizing of 200 United Nations hostages.
The 64-year-old insisted the Serbs were only acting in self-defence and that any conflict resulting from the break-up of the former Yugoslavia in the 1990s was a natural consequence of Serbs, Croats and Muslims fighting for land.
Karadzic, often referring to himself in the third person, has two days to deliver his opening statement, followed by the start of the prosecutors' case against him. He spoke almost non-stop for three hours, with just a short break.
"I will defend that nation of ours and their cause that is just and holy. We have a good case. We have good evidence and proof," he said in his opening statement at the international criminal tribunal for the former Yugoslavia (ICTY) in The Hague.
Karadzic sought to portray the Serbs as the victims, blaming the former Croat leader Franjo Tudjman and the former Bosnian Muslim leader Alija Izetbegović of pursuing "ethnocentric" aims, with the desire to create Croatian and Bosnian Muslim states respectively. An indictment would be more believable against Croatian and Bosnian Muslim rather than Serbian leaders, Karadzic told the court.
He accused Turkey of wanting to re-establish an "Ottoman" presence in the Balkans and restore a "stability of the cemetery". Karadzic repeatedly said the Serbs were reacting to events and only took action to defend themselves. "My generals were taking action to defend Serbs … against a raging bull."
Prosecutors were trying to present him as a monster because they did not have any evidence that he had committed a crime, Karadzic said. "This indictment should not have been issued in the first place."
He rejected charges that the Serbs ran concentration camps where non-Serbs were tortured and killed, saying the camps were "collection centres" for refugees. "It was a transit point for persons who had nowhere to go because of the fighting going on around them," he said.
He denied that Serb forces deliberately targeted a market during the siege of Sarajevo, an attack that killed 68 people.
Prosecutors say Karadzic orchestrated a campaign to destroy the Muslim and Croat communities in eastern Bosnia to create an ethnically pure Serbian state. He denies any guilt – although he refused to enter a formal plea – and could face life in prison if convicted.
The Bosnian war included the 44-month siege of the capital, Sarajevo, and the torture and murder of hundreds of prisoners in detention camps, and culminated in the massacre of around 8,000 Muslim males in one week in July 1995. The massacre, in the Srebrenica enclave, was the worst in Europe since the second world war.
In his opening statement last October the prosecutor, Alan Tieger, said Karadzic "harnessed the forces of nationalism, hatred and fear to pursue his vision of an ethnically segregated Bosnia".
Karadzic is the most important figure to be brought to trial since the former Yugoslav president Slobodan Milosevic, who died of a heart attack in 2006 before his case was concluded.
As president of the breakaway Bosnian Serb state, Karadzic negotiated with diplomats, UN officials and peace envoys. He set the tone and pace of the 1992-95 Bosnian war, in which an estimated 100,000 people died.
Karadzic – who is representing himself despite his lack of legal training – has persistently attempted to stall the trial. On Friday the three-judge tribunal dismissed his request to adjourn the trial until June after his two-day opening statement and ordered prosecutors to present their first witness on Wednesday.
Karadzic boycotted the opening of the trial four months ago, prompting the court to suspend the case.