When the Bosnian Serb assembly voted to create a military in 1992, Mladic was appointed the commander. He was the second most powerful Bosnian Serb figure after Radovan Karadzic, the Bosnian Serb political leader. He was dismissed from his post by Karadzic in 1996. At the time of his arrest, Mladic was the most senior wanted official from the Bosnian wars (Slobodan Milosevic being dead and Karadzic already detained).
Prior to being appointed head of the Bosnian Serb Army, Mladic served as a top military official in the Yugoslav People’s Army (JNA). He began the four-year Siege of Sarajevo in 1992 while still with the JNA.