The lines of command and control in the occupied territory were never unified, and were made more complex by the appointment of direct representatives of senior Nazi figures such as Reichsführer-SS Heinrich Himmler (for police and security matters), Reichsmarschall Hermann Göring (for the economy), and Reichsminister Joachim von Ribbentrop (for foreign affairs).

In late July 1941, an uprising began in the occupied territory, which quickly swamped the Serbian gendarmerie, German police and security apparatus, and even the rear area infantry force.

The one area in which the puppet administration did exercise initiative and achieve success was in the reception and care of hundreds of thousands of Serb refugees from other parts of partitioned Yugoslavia.

During the occupation, the German authorities killed nearly all Jews residing in the occupied territory, by shooting the men as part of reprisals conducted in 1941, and gassing the women and children in early 1942 using a gas van.

The first military commander in the occupied territory was General der Flieger[a] Helmuth Förster, a Luftwaffe officer, appointed on 20 April 1941,[31] assisted by the chief of the administrative staff, SS-Brigadeführer[b] and State Councillor, Dr. Harald Turner.

[27] In a sign of things to come, on the day after the capitulation of Yugoslavia, the SS Motorised Infantry Division Reich had executed 36 Serbs in reprisal for the killing of one member of that formation.

[39] In May, the KPJ outlined its policy of "unity and brotherhood among all peoples of Yugoslavia, [and] relentless struggle against the foreign enemies and their domestic helpers as a matter of sheer survival".

In late April, Yugoslav Army Colonel Draža Mihailović and a group of about 80 soldiers, who had not followed the orders to surrender, crossed the Drina river into the occupied territory, having marched cross-country from the area of Doboj, in northern Bosnia, which was now part of the NDH.

[42] By the end of May, Mihailović had decided that he would adopt a long-term strategy aimed at gaining control over as many armed groups as possible throughout Yugoslavia, in order to be in a position to seize power when the Germans withdrew or were defeated.

[43] Hitler had briefly considered erasing all existence of a Serbian state, but this was quickly abandoned and a search began for a suitable Serb to lead a collaborationist regime.

[50] During May 1941, Förster issued numerous orders, which included a requirement for the registration of all printing equipment, restrictions on the press, operation of theatres and other places of entertainment, and the resumption of production.

[62] Bader's command also included the 12th Panzer Company zbV, initially equipped with about 30 captured Yugoslav Renault FT tankettes, and a motorized signals battalion.

[61] The four Landesschützen battalions fell far short of the numbers needed for guarding tasks throughout the territory, which included; bridges, factories, mines, arms dumps of captured weapons, and shipping on the Danube.

[47] Refugees escaping persecution in the Independent State of Croatia, and others fleeing Bulgarian-annexed Macedonia, Kosovo and Hungarian-occupied Bačka and Baranja had begun to flood into the territory.

This meeting resolved to shift to a general uprising, form Partisan detachments of fighters and commence armed resistance, and call for the populace to rise up against the occupiers throughout Yugoslavia.

[75] At the end of July, two battalions of the 721st Regiment of the 704th Infantry Division were sent to suppress rebels in the Banat region, who had destroyed large wheat stores in the Petrovgrad district.

[79] In response to the revolt, the Aćimović administration encouraged 545 or 546 prominent and influential Serbs to sign the Appeal to the Serbian Nation, which was published in the German-authorized Belgrade daily newspaper Novo vreme on 13 and 14 August.

[71] Aćimović also gave orders that the wives of communists and their sons older than 16 years of age be arrested and held, and the Germans burned their houses and imposed curfews.

[53] On 13 August, Bader reneged on Danckelmann's pledge to allow the Commissioner Government to maintain control the Serbian gendarmerie, and ordered that they be re-organized into units of 50 to 100 men under the direction of local German commanders.

[91] To strengthen the puppet government, Danckelmann wanted to find a Serb who was both well-known and highly regarded by the population who could raise some sort of Serbian armed force and who would be willing to use it ruthlessly against the rebels whilst remaining under full German control.

[71] In response to a request from Benzler, the Foreign Office sent SS-Standartenführer Edmund Veesenmayer to provide assistance in establishing a new puppet government that would meet German requirements.

[93] Veesenmayer engaged in a series of consultations with German commanders and officials in Belgrade, interviewed a number of possible candidates to lead the new puppet government, then selected former Yugoslav Minister of the Army and Navy General Milan Nedić as the best available.

The Germans had to apply significant pressure to Nedić to encourage him to accept the position, including threats to bring Bulgarian and Hungarian troops into the occupied territory and to send him to Germany as a prisoner of war.

[118] After a few days break, on 19 and 20 October the 342nd Infantry Division conducted its third major operation, aimed at clearing the Jadar region and the main centre of insurgent activity in that area, Krupanj.

[123] In January 1943, Nedić proposed a basic law for Serbia, in effect a constitution creating an authoritarian corporative state similar to that long advocated by Dimitrije Ljotić and his pre-war fascist Yugoslav National Movement.

This decision reflected the anger Hitler felt against Serbs, who he saw as the main instigators of the Belgrade military coup of 27 March 1941 which brought down the Yugoslav government that had acceded to the Tripartite Pact two days earlier.

[132] After discussions with both the Romanian and Hungarian governments, Hitler decided that the Vojvodina region would be divided by the river Tisa, with the eastern portion (the Serbian Banat) being placed under German occupation along with "Old Serbia".

[140] For example, the plenipotentiary for economic affairs, Franz Neuhausen, who was Göring's personal representative in the occupied territory, was directly responsible to the Reichsmarshall for aspects of the German Four Year Plan, and had complete control over the Serbian economy.

[146] 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.

[176] Collaborationist armed formations forces were involved, either directly or indirectly, in the mass killings of Jews, Roma and those Serbs who sided with any anti-German resistance or were suspects of being a member of such.