The former leader of rebel Serbs in Croatia, Goran Hadzic, has died. He was 58.

The Hospital Center said Hadzic, who had brain cancer, died Tuesday at the hospital in Novi Sad in northern Serbia.

Hadzic was arrested in 2011 and faced war crimes charges for his leadership of a campaign to carve off one-third of Croatia and join it to the Serb-dominated parts of eastern Croatia.

The U.N. war crimes tribunal in the Hague dropped the case against him because of his terminal illness and released him from jail last year.

Hadzic had pleaded not guilty to involvement in the murder of hundreds of Croats and expulsion of tens of thousands more from their homeland during Croatia's 1991-95 war when ethnic Serbs rebelled against independence from the Serb-led Yugoslavia.