The capture of Radovan Karadzic raises the question of whether his arch ally General Ratko Mladic could soon be in detention too.
The former career military officer was Karadzic's army chief throughout the 1992 to 1995 Bosnian war and is wanted by the International Criminal Tribunal for the former Yugoslavia.
He was indicted in 1995 for genocide, crimes against humanity and war crimes in connection with among other events, the siege of Sarajevo and the massacre of around 8,000 Muslims at Srebrenica in 1995, the worst atrocity in Europe since the Second World War.
At the end of the Bosnian war, Mladic returned to Belgrade, where he enjoyed the open support and protection of the late Serbian leader Slobodan Milosevic.
He lived openly in the city - visiting public places, eating in expensive restaurants and even attending football matches until Milosevic was arrested.
Now aged 66, his whereabouts are not known, but is believed that he could be hiding in Serbia with the help of hard-liners in the police and military and Serb loyalists.
In 2005, it was reported that Mladic had demanded more than £2 million in "compensation" to be given to his family and bodyguards if he gave himself up to the tribunal.
Described by Interpol as of stocky build and with a "highly coloured complexion" Mladic is said to be in poor health.
In June 2006 there were reports that he had suffered a third stroke and that he had low chances of survival.
"That Ratko Mladic is still at liberty is a major obstacle to full accountability for the genocide at Srebrenica," said Richard Dicker, director of Human Rights Watch's International Justice Programme.
"The EU must insist that Serbia surrender him."Reuse content