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. Other parts of modern Serbia that were not included in the German-administered territory were occupied and annexed by neighboring Axis countries: Syrmia was occupied and annexed by the Independent State of Croatia, Bačka was occupied and annexed by Hungary, southeastern Serbia was occupied and annexed by Bulgaria, and southwestern Serbia was occupied and annexed by Italy and included in the Italian protectorates of Albania and Montenegro. German occupation The area under control of the German Military Administration in Serbia was initially occupied by the Germans. It was later occupied mostly by Bulgarian troops, but remained under German military authority. On stamps and coins this territory was referred to as Serbia, and, according to Professor Paul N. Hehn, its official name was the Territory of the Military Commander in Serbia. This territory had two successive Serbian puppet governments which were under the control of the German military authorities. The first short-lived puppet government was known as the Commissioner Government and was led by Milan Aćimović. The second puppet government was known as the Government of National Salvation and was led by Milan Nedić. Of the Jewish population of about 12,500 in Serbia, under German occupation controlled by Hungary or the Independent State of Croatia, approximately 11,000 Jews were murdered. Italian-Albanian occupation The line between the German-occupied area and the Italian Albania in the Kosovo region was the cause of a significant clash of interests, mainly due to the important lead and zinc mines at Trepča and the key railway line Kosovska Mitrovica–Pristina–Uroševac–Kačanik–Skopje. Ultimately the Germans prevailed, with the "Vienna Line" extending from Novi Pazar in the Sandžak through Kosovska Mitrovica and Pristina, along the railway between Pristina and Uroševac and then towards Tetovo in modern-day North Macedonia before turning northeast to meet Bulgarian-annexed territory near Orlova Čuka. The Kosovska Mitrovica, Vučitrn and Lab districts, along with part of the Gračanica district were all part of the German-occupied territory. This territory included a number of other important mines, including the lead mine at Belo Brdo, an asbestos mines near Jagnjenica and a magnesite mine at Dubovac near Vučitrn. The Sandžak