The summer of 1942 marked the high tide of German success in the East. In October 1942 the Germans established in the Kuban a semi-autonomous Cossack District and were now in the position to recruit Cossacks from these areas, the POW camps, and defectors from the Red Army. Of the latter, the most significant was the desertion of an entire Red Army regiment (Infantry Regt. 436) which, with all officers, went over to the Germans on August 1941. Its commander, Major I.N.Kononov, was a Don Cossack. He had a distinguished career in the German service, ending the war as Major General in the XVth Cossack Cavalry Corps under the command of the German General Helmuth von Pannwitz.
Already in May 1943 Pannwitz was given authorization to create a first Cossack Division consisting of two brigades which trained throughout the summer in Mława (Mielau), north of Warsaw. The division was then not, as it had hoped, sent to fight the Red Army, but instead it was ordered, in September 1943, to proceed to Yugoslavia and fight Josip Broz Tito's partisans. The Cossacks took part in several major offensives against the Partisans including Operation Rösselsprung, the attack on Tito's headquarter in Bosnia from which Tito evaded capture only by the narrowest of margins. During the summer of 1944 the two brigades were upgraded to become the 1st Cossack Cavalry Division and 2nd Cossack Cavalry Division. From the beginning of 1945, these divisions were combined to become XVth Cossack Cavalry Corps.
By the end of the war, the SS took control of all foreign units within the German forces. The Himmler file in the Imperial War Museum contains a record of a conversation which occurred on August 26, 1944, between Himmler, General von Pannwitz, and his Chief of Staff, Colonel H.-J. von Schultz. An agreement was reached that the Cossack divisions, soon to be the Cossack Corps, would only be placed under SS administration in terms of replacements and supplies. However, by February 1, 1945 the corps was transferred to the Waffen-SS. Despite the refusal of General von Pannwitz to enter the SS, the corps was placed under SS administration and all Cossacks became formally part of the Waffen-SS.