During World War II, several provinces of the Kingdom of Yugoslavia corresponding to the modern-day state of Serbia were occupied by the Axis Powers from 1941 to 1944.
Most of the area was occupied by the Wehrmacht and was organized as separate territory under control of the German Military Administration in Serbia.
[7] After discussions with both the Romanian and Hungarian governments, Adolf Hitler decided that the Bačka and Banat region would be divided by the river Tisa, with the eastern portion under German occupation along with "Old Serbia".
[9] An area of eastern Syrmia was initially included in the occupied territory for military and economic reasons, especially given Belgrade's airport and radio station were located there.
During this early period the border between the occupied territory and the NDH ran between the villages of Slankamen on the Danube and Boljevci on the Sava.
[10] In 1941 some parts of Serbia, including Vranje, Bosilegrad, Caribrod and Pirot were occupied and subsequently annexed by Bulgaria.
This corps was initially responsible for about 40% of the territory (excluding the Banat), bounded by the Ibar river in the west between Kosovska Mitrovica and Kraljevo, the West Morava river between Kraljevo and Čačak, and then a line running roughly east from Čačak through Kragujevac to the border with Bulgaria.
[13] This released the 7th SS Volunteer Mountain Division Prinz Eugen, which had been garrisoning this area over the winter, to deploy into the NDH and take part in Case White against the Partisans.
From this point, German forces only directly occupied the immediate area of Belgrade, the northwest region of the territory that shared a border with the NDH, and the Banat.