Germany, Italy, Hungary, and Bulgaria dismembered Yugoslavia. Germany occupied a rump Serbia and part of Vojvodina (see fig. 5). It created a puppet "Independent State of Croatia" (Nezavisna drzava Hrvatska, NDH) including Croatia and Bosnia and Hercegovina, and it annexed northern Slovenia. Italy won southern Slovenia and much of Dalmatia, joined Kosovo with its Albanian puppet state, and occupied Montenegro. Hungary occupied part of Vojvodina and Slovenian and Croatian border regions. Bulgaria took Macedonia and a part of southern Serbia.

Germany unleashed a reign of terror and Germanization in northern Slovenia. It resettled Slovenes in Serbia, moved German colonists onto Slovenian farms, and attempted to erase Slovenian cultural institutions. The Catholic hierarchy collaborated with the authorities in Italian-occupied southern Slovenia, which suffered less tyranny than the north.

Germany and Italy supported the NDH and began diverting natural resources to the Axis war machine. When Macek refused to collaborate, the Nazis made Ante Pavelic head of the NDH. His Ustase storm troopers began eliminating the two million Serbs, Jews, and Gypsies in the NDH, through forced religious conversion, deportation, and extreme violence. The NDH was backed enthusiastically by some Croatian Catholic clergy, including the Archbishop of Sarajevo; some Franciscan priests enlisted in the Ustase and participated in massacres. The Archbishop of Zagreb, Alojzije Stepinac, publicly welcomed and appeared with Paveli while privately protesting NDH atrocities. On the other hand, many Catholic priests condemned the violence and helped Orthodox Serbs to practice their religion in secret. Even the Germans were appalled by Ustase violence, and Berlin feared the bloodbath would ignite greater Serbian resistance. Italy reoccupied areas of Hercegovina to halt the slaughter there.

Jews and Serbs also were massacred in areas occupied by the Albanians and the Hungarians. Thousands of Serbs fled to Serbia, where the Germans had established a puppet regime under General Milan Nedic. Nedic considered himself a custodian rather than a collaborator and strove to maintain control of violence. In the south of Yugoslavia, many Macedonians welcomed Bulgarian forces, expecting that Sofia would grant them autonomy; but a harsh Bulgarianization campaign ended their enthusiasm.

Resistance in Yugoslavia developed mainly in dispersed units of the Yugoslav army and among Serbs fleeing genocide in Croatia and Bosnia and Hercegovina. Various armed groups in Serbia organized under the name Cetnik (pl. Cetnici--see Glossary), from the Serbian word for "detachment." Some Cetnici supported Nedic, others the Communist-led Partisan guerrillas. The best known Cetnici were the followers of Colonel Draza Mihajlovic, a Serbian nationalist, monarchist, and staunch anticommunist. Certain that the Allies would soon invade the Balkans, Mihajlovic advised his Cetnici to avoid clashes with Axis forces and prepare for a general uprising to coincide with the Allied push. In October 1941, Britain recognized Mihajlovi as the leader of the Yugoslav resistance movement, and in 1942 the government-in-exile promoted him to commander of its armed forces.

Data as of December 1990