The trial of four Bosnian Serb officers over the slaughter of thousands of Muslims in Srebrenica during the Bosnian war, opens before the UN court in the Hague next Tuesday.
More than 7,000 Muslim men were massacred when Bosnian Serb troops led by General Ratko Mladic overran the Muslim enclave in July 1995.
The defendants - Vidoje Blagojevic, Dragan Obrenovic, Momir Nikolic and Dragan Jokic - are charged with "knowingly participating in a joint criminal enterprise, the common purpose of which was ... to summarily execute by firing squad, bury and rebury thousand of Bosnian Muslim men and boys aged 16 to 60 from the Srebrenica enclave".
Dutch peacekeepers sent by the United Nations to protect Srebrenica failed to prevent the mass killing spree, the bloodiest incident in the wars surrounding the break-up of the former Yugoslavia in the 1990s.
The trial will be the second concerning the Srebrenica massacre. In 2001 Bosnian Serb General Radislav Krstic was convicted and sentenced to 46 years in prison - the heaviest sentence yet passed by the court - for what it ruled was orchestrated genocide in the enclave.
The verdict was also the first time the International Criminal Tribunal for the former Yugoslavia (ICTY) had formally recognised that genocide occurred in Bosnia.
The men who go on trial are all subordinates of Krstic, who led the Drina corps of the Bosnian Serb army.
The defendants have all pleaded not guilty to the charges in pre-trial hearings.
The second Srebrenica trial at the UN war crimes court turns the spotlight on two of the tribunal's most wanted fugitives: Bosnian Serb wartime leader Radovan Karadzic and his military commander Mladic. Both are charged with genocide specifically for the massacre but are still at large despite intense international pressure for their capture.
Karadzic is believed to be hiding in the Republika Srpska, the Bosnian Serb entity, while Mladic is thought to be in Serbia under the protection of the army there. In a new development last week the Serbian authorities ordered the army to arrest Mladic if he does not surrender to the ICTY.
Since the end of the Bosnian war thousands of human remains have been exhumed from over 60 mass graves near Srebrenica.