Francetić earned his only military education and officer rank while serving the Kingdom of Yugoslavia Army. He became a non-commissioned officer in the rank of sergeant. About Francetić's military experience and knowledge, his Ustashe superior Eugen Dido Kvaternik wrote: "He did not have basic military knowledge nor military education, nor did he have any talent for basic military organization.". After establishment of the Independent State of Croatia in April 1941 he and other 10 Ustašas organized the Black Legion (Croatian: Crna Legija). Jure Francetić became the leader of the Black Legion and earned the rank of colonel in the Ustaša army. Kvaternik believed that Francetić "a born guerrilla and a son of our mountainous Hercegovina" was the reason good enough to put him in the role of military leader in Bosnia and Herzegovina. In order to consolidate the Ustashe party power, much of the party work in the province he put in the hands of Catholic priests. Francetić's Ustashe took control over the local administration by dismissing all civil servants and teachers belonging to the category of "Srbijanci", as well as those who were Jews. Killings, arrests, and deportation of Serbs and Jews was a regular duty of Francetić's henchmen - based and justified by the official Ustashe policy which demanded total extermination of Jews and murder, expulsion, and conversion to the Roman Catholicism of Serb population in Bosnia and Herzegovina. Francetić participated personally in arresting and interrogations of prominent Serbian and Jewish leaders (Vaso Miskin, Albahari) and ordered the murders of some of them. He even turned his own Sarajevo apartment into the prison kitchen and laundry room.