Speaking for the first time at the International Criminal Tribunal for the former Yugoslavia (ICTY), the former Bosnian Serb leader also accused prosecutors of using "tricks" to fabricate some of the evidence used to charge him with genocide, war crimes and crimes against humanity.
"I will defend that nation of ours and their cause that is just and holy," Karadzic said as he made his opening statements at the trial.
The gray-haired 64-year-old, who is defending himself in court, had refused to attend the trial's opening in late October. He then prompted a four-month delay by asking for more time to prepare his case.
His defense team has asked for permission to appeal a court decision on Friday not to grant him yet more time.
Karadzic is the best-known Serbian leader to have been brought to trial in The Hague since Slobodan Milosevic, the late Yugoslav president who died four years ago while being tried for crimes against humanity in the Dutch capital.
First indicted in 1995, the former Bosnian Serb leader was arrested in July 2008 in Belgrade, where he had been hiding disguised as the long-bearded Dragan David Dabic, doctor of alternative medicine.
He denies all 11 charges brought against him by UN prosecutors, including two counts of genocide for acts committed during the 1992-1995 Bosnian War, which left more than 100,000 dead and over two million displaced.
He faces a possible life sentence if found guilty at the trial, which could last years.
The founding member of the Serbian Democratic Party of Bosnia and Herzegovina is alleged to have orchestrated the 1992-1995 siege of Sarajevo and the 1995 massacre in the Muslim enclave of Srebrenica, then a UN-declared "safe zone," where Bosnian Serb forces killed close to 8,000 unarmed Muslim men and boys.
According to the indictment papers of ICTY, Karadzic sought "the permanent removal of Bosnian Muslims and Bosnian Croats from Bosnian Serb-claimed territory" in Bosnia during the first half of the 1990s.
But Karadzic told judges Monday he would use "marble-solid evidence" to prove that "there was never a plan nor an idea to expel Muslims from the Republic Srpska," the Serb territory within Bosnia-Herzegovina he headed during the 1990s.
