Despite the best efforts of a number of historians, many aspects of the ferocious struggle between Nazi Germany and the Soviet Union during the Second World War remain obscure or shrouded in myth. One of the most persistent of these is the notion - largely created by many former members of its own officer corps in the immediate postwar period - that the German Army was a paragon of military professionalism and operational proficiency whose defeat on the Eastern Front was solely attributable to the amateurish meddling of a crazed former Corporal and the overwhelming numerical superiority of the Red Army. A key pillar upon which the argument of German numerical-weakness vis-à-vis the Red Army has been constructed is the assertion that Germany was simply incapable of providing its army with the necessary quantities of men and equipment needed to replace its losses. In consequence, as their losses outstripped the availability of replacements, German field formations became progressively weaker until they were incapable of securing their objectives or, eventually, of holding back the swelling might of the Red Army. This work seeks to address the notion of German numerical-weakness in terms of Germany's ability to replace its losses and regenerate its military strength, and assess just how accurate this argument was during the crucial first half of the Russo-German War (June 1941-June 1943). Employing a host of primary documents and secondary literature, it traces the development and many challenges of the German Army from the prewar period until the invasion of the Soviet Union in June 1941. It continues on to chart the first two years of the struggle between Germany and the Soviet Union, with a particular emphasis upon the scale of German personnel and equipment losses, and how well these were replaced. It also includes extensive examinations into the host of mitigating factors that both dictated the course of Germany's campaign in the East and its replacement and regeneration capabilities. In contrast to most accounts of the conflict, this study finds that numerical-weakness being the primary factor in the defeat of the Ostheer - specifically as it relates to the strength and condition of the German units involved - has been overemphasized and frequently exaggerated. In fact, Germany was actually able to regenerate its forces to a remarkable degree with a steady flow of fresh men and equipment, and German field divisions on the Eastern Front were usually far stronger than the accepted narratives of the war would have one believe.