Momcilo Krajisnik is one of the highest-ranking Bosnian Serb politicians to stand trial before the International Criminal Tribunal for the former Yugoslavia (ICTY).
Accused of masterminding a brutal campaign of "ethnic cleansing" that killed large numbers of non-Serbs during the war in Bosnia-Hercegovina, he goes on trial on Tuesday.
Besides the specific charge of genocide, the court is looking into alleged acts committed with the intent to destroy in whole or in part, a national, ethnic, racial or religious group. He also faces charges of complicity in genocide.
Usually, suspects before the UN court are charged either with genocide or with complicity in genocide, as is the case with former Yugoslav president Slobodan Milosevic.
The fact that Krajisnik faces two separate genocide charges reflects his alleged key role in "ethnic cleansing".
The hardline Serb nationalist is accused of planning and ordering widespread killings of Bosnian Croats and Muslims during attacks on villages and killings in various detention centres.
Many thousands of non-Serbs were held in inhumane conditions and subjected to torture and physical and sexual abuse. In all, the war in Bosnia left over 200,000 people dead.
Radovan Karadjic is on the run
from SFOR and Bosnian police
Krajisnik is also charged with five counts of crimes against humanity, including persecution, murder, deportation and one charge of war crimes. If convicted, he could face a life sentence.
An ally of Bosnian Serb wartime leader and fugitive, Radovan Karadzic, the 59-year-old Krajisnik is a fiercely anti-Muslim nationalist who held the post of speaker of the Bosnian Serb parliament.
He was the most senior Bosnian Serb leader present at the Dayton peace talks, which led to the end of the war in 1995. His inflexible stance at the negotiation table earned him the nickname of "Mr No".
The prosecution claims that Krajisnik's "had de facto control and authority over the Bosnian Serb forces and Bosnian Serb political and governmental organs, who participated in the crimes alleged in the indictment" because of his prominent political position.
Along with Karadzic and Milosevic, he is also accused of being a member of a joint criminal enterprise whose aim was "the partial destruction of the Bosnian Muslim and Bosnian Croat national, ethnical, racial or religious groups in the territories of Bosnia and Hercegovina".
Krajisnik was originally set to be tried with former Bosnian Serb President Biljana Plavsic, but she made a surprise guilty plea in October 2002 to charges of crimes against humanity and was sentenced in February 2003 to 11 years in prison.
In her plea, Plavsic named Krajisnik together with Karadzic, Milosevic and wartime Bosnian Serb army leader Ratko Mladic as the masterminds of the campaign to forcibly drive non-Serbs out of Serb-dominated areas in Bosnia.
Mladic, who like Karadzic is charged with genocide, is still on the run.
After the Dayton peace accords, in the first post-war elections Krajisnik was elected to the joint presidency of Bosnia alongside Muslim leader Alija Izetbegovic and Bosnian Croat Kresimir Zubac. He was not re-elected in the 1998 elections.
In April 2000, Krajisnik was arrested by SFOR troops in Bosnia and brought to the tribunal. At his initial hearing, he pleaded not guilty to all counts. His trial is expected to last several months.