German high mountain battalion, Elbrus, Caucasus, south-east Russia, 1943. The German advance into the Soviet Union reached the Caucasus in 1942, its deepest penetration into Russian territory. Soviet counter-offensives in the winter of 1942-1943 and the German defeat at Stalingrad began the long retreat for Hitler's armies however. A print from 'Signal', January 1943. 'Signal' was a magazine published by the German Third Reich from 1940 through 1945. Credit: Art Media / HIP / TopFoto