The Banjica concentration camp (, ) was a Nazi German concentration camp in the Territory of the Military Commander in Serbia, the military administration of the Third Reich established after the Invasion and occupation of Yugoslavia during World War II. In response to escalating resistance, the German army instituted severe repressive measures – mass executions of civilian hostages and the establishment of concentration camps. Located in the Banjica neighborhood of Dedinjea suburb of Belgradeit was originally used by the Germans as a center for holding hostages. The camp was later used to hold anti-fascist Serbs, Jews, Roma, captured Partisans, Chetniks and other opponents of Nazi Germany. By 1942, most executions occurred at the firing ranges at Jajinci, Marinkova Bara and the Jewish cemetery. Banjica was operational from July 1941 to October 1944. It was jointly run by German occupiers under the command of Gestapo official Willy Friedrich and the Milan Nedić's puppet government, which was under full control of the occupational forces. However although German forces took the leading and guiding role of the Final Solution in Serbia, and the Germans monopolized the killing of Jews, they were actively aided in that role by Serbian collaborators. Later, Friedrich was tried, found guilty and executed for war crimes by Yugoslavia's post-war communist authorities. 23,697 individuals were detained in Banjica throughout the war, at least 3,849 of whom perished. After the war, a small monument dedicated to the victims of the camp was constructed. The site is now a museum. Background Prelude to the occupation Following the 1938 Anschluss between Germany and Austria, Yugoslavia shared a border with the Third Reich and came under increasing pressure as her neighbours aligned themselves with the Axis powers. In April 1939, Italy opened a second frontier with Yugoslavia when it invaded and occupied neighbouring Albania. At the outbreak of World War II, the Yugoslav government declared its neutrality. Between September and November 1940, Hungary and Romania joined the Tripartite Pact, aligning themselves with the Axis, and Italy invaded Greece. From that time, Yugoslavia was almost completely surrounded by the Axis powers and their satellites, and her neutral stance toward the war became strained. In late February 1941, Bulgaria joined the Pact. The following day, German troops entered Bulgaria from Romania, closing the ring around Yugoslavia. Intending to secure his southern flank for the impending attack on the Soviet Union, Adolf Hitler began placing heavy pressure