The notorious figure known as the "Butcher of Bosnia" was Radovan Karadžić. He was a political leader during the Bosnian War and was charged with war crimes for his role in ethnic cleansing and genocide against Bosniaks and Croats. His actions and policies during the conflict significantly contributed to the suffering and loss of life in the region, ultimately leading to his arrest and conviction at the International Criminal Tribunal for the former Yugoslavia.