Einsatzgruppe Serbia
Helm was a protege of the senior Gestapo official, Heinrich Müller, and his appointment to the position was encouraged by Jovanović and Aćimović, whom he had met when they visited Berlin.
The German ambassador, Viktor von Heeren, was a former member of the diplomatic corps of the pre-Nazi Weimar Republic, and was wary of Helm and his role, and concerned about what impact the Gestapo official would have on Germany's relationship with the Stojadinović government.
However, both men maintained their contact with Helm, with Jovanović allegedly permitting a secret German Abwehr (military intelligence) radio to be installed in his home.
In addition to his intelligence work, Helm also collected commercial information, helping a German company obtain a concession to explore for oil in Yugoslavia ahead of British interests.
This responsibility fell to SS-Sturmbannführer Karl Kraus, who belonged to Amt VI of the RSHA, the Ausland-Sicherheitsdienst (Foreign Intelligence Service, or Ausland-SD).
[8] Kraus was responsible for organising fifth column activities among the ethnic Germans of Yugoslavia, and ran lectures for them at the former Czechoslovakian embassy in Belgrade.
[11] In the spring of 1940, Nassenstein was transferred to Zagreb to consolidate contacts among Croatian separatists and counter the work of the British and French intelligence services there.
[12] Following the 1938 Anschluss between Germany and Austria, Yugoslavia came to share a border with the Third Reich and fell under increasing pressure as her neighbours aligned themselves with the Axis powers.
[15] Intending to secure his southern flank for the impending attack on the Soviet Union, Adolf Hitler began placing heavy pressure on Yugoslavia to join the Axis.
Two days later, a group of pro-Western, Serbian nationalist Royal Yugoslav Army Air Force officers deposed the country's regent, Prince Paul, in a bloodless coup d'état, placed his teenaged nephew Peter on the throne, and brought to power a "government of national unity" led by General Dušan Simović.
[8] Immediately following the coup, Heydrich summoned SS-Sturmbannführer Walter Schellenberg, the acting head of the Ausland-SD, and ordered him to compile a list of all Yugoslavs who were opposed to Nazi Germany, so they could be arrested during and after the pending invasion.
On 1 April, Fuchs went to Vienna, where he gathered about 60 SD and Gestapo officials, including experts in Yugoslavian affairs such as Helm and SS-Sturmbannführer Wilhelm Beissner, who was head of the Yugoslav section of the Ausland-SD office in Berlin.
The Germans had engineered and supported the creation of the NDH, which roughly comprised most of the pre-war Banovina Croatia, along with rest of present-day Bosnia and Herzegovina and some adjacent territory.
One of these SS-SKs, commanded by SS-Sturmbannführer Karl Hintze, located the Patriarch of the Serbian Orthodox Church, Gavrilo V, whose name was on the list given to Fuchs.
[24] In the first weeks of the occupation, EK Belgrade's SS-Obersturmführer Fritz Müller led a SS-SK in searching for those on the list, but he lacked the manpower for the task, and relied heavily on the Abwehr and Geheime Feldpolizei (Secret Field Police), to locate and arrest the wanted people.
[25] This search for wanted persons was the main initial task of EG Yugoslavia, and resulted in the sending of many arrested people to the Gestapo in Graz, or to concentration camps in the Third Reich.
