'Kammerjäger' was an Axis operation to check the arrival of fresh partisan units of Marshal Josip Broz Tito’s forces in the Serb region of German-occupied Yugoslavia (mid-March 1944).

At the start of this period the partisan movement’s 2^nd Proletarian Division and 5^th Assault Division attempted to enter Serbia from Sandzak with the object of crossing the areas of Ibar and Kopaonik to reach south-eastern Serbia, where they were to join the local partisan forces, the largest and best organised communist units in Serbia, and thus form the basis for increased resistance across the whole of Serbia. Simultaneously the partisan III Corps was to advance into western Serbia, but this attempt was foiled by 'Maibaum'.

The two Yugoslav divisions were meet by a determined resistance by German, Bulgarian, pro-German Serb and Četnik forces, and forced to turn to the north-west. Tito and his staff believed that the Germans were unaware of their plan, but their radio communications were being monitored by Germans, who easily broke the partisan codes and were thus in complete possession of the details of the plan and therefore well able to lay their own preparations.

Initially the Germans ordered only General Major Simeon Simov’s Bulgarian 24^th Division together with Četnik and Serb collaborationist forces to halt the partisan advance, but these proved inadequate and General Hans-Gustav Felber, the Militärbefehlshaber 'Südost', began preparation for a large-scale operation involving some 22,000 Axis troops. The German units included the 4^th Regiment of Generalmajor Alexander von Pfuhlstein’s Division 'Brandenburg', 696^th Feldgendarmeriebataillon (mot.), 3/2^nd and 7/2^nd Polizeiregiment, 2/3^rd Polizeiregiment, two companies of Generalleutnant Otto Gullmann’s 297^th Division, elements of Boris F. Shteyfon’s Russkiy Okhranniy Korpus (later Russisches Schutzkorps and later still Russisches Schutzkorps Serbien), 10 tanks of the 5^th SS Polizeiregiment and, to secure local railways, the 205^th Panzerzug and 301^st Panzerzug armoured trains.

The Bulgarian formations were the 24^th Division and General Major Nikola Grozdanov’s 25^th Division. The Serb State Guard units were the 'Tranvski' District Company, 'Zički' District Company and 'Kraljevac' District Company, while the Serb Volunteer Corps' units were the 1/1^st Regiment, 2^nd Regiment and 4^th Regiment. The 10,000 Četniks came from the Pozega Corps, 1^st and 2^nd Takovo Brigades of the 1^st Ravna Gora Corps, 2^nd Ravna Gora Corps, Lieutenant Colonel Dragutin Keserović's Rasinski Corps, Javorski Corps and 2^nd Kosovo Corps.

After two months of heavy fighting, both of the partisan divisions were forced to retreat back to Sandak after suffering comparatively heavy losses: the 2^nd Proletarian Brigade lost 34 men killed, 101 wounded and 60 missing, while the 5^th Division lost 106 men killed, 324 wounded, 15 died from wounds and disease, and 27 missing.