During the Second World War, after the German invasion of the Soviet Union on 22 June 1941, the district was occupied by the Wehrmacht, and, in 1942, the inhabitants, both Swedes and Germans whom the Nazis considered together as "ethnic Germans" ("Volksdeutsche", in German) and others (such as Ukrainians), were assessed and inventoried by officers of the Reichssippenamt operating under the direction of Kommando Karl Stumpp, the former historian of the area. As a result of the impending German onslaught, the Soviet authorities had already exiled many of the adult males among the ethnic German population of the district to areas of refuge and captivity east of the Ural mountains. During the German occupation, the area was officially under the Nazi civil administration of the Reichskommissariat Ukraine until the Soviet Red Army's successful counteroffensive drove the occupation forces, both military and civil, from the region in 1944.