Operation Barbarossa was the largest invasion in history. Almost 3.5 million men smashed into Stalin’s Red Army, reaching the gates of Leningrad, Moscow, and Sevastopol. But not all of this vast army was German; by the summer of 1942, over 500,000 were Romanians, Italians, Hungarians, Slovaks, and Croatians—Hitler’s Axis allies. As part of the German offensive that year, more than four allied armies advanced to the Don, only to be annihilated in the Red Army’s Saturn and Uranus winter offensives. Hundreds of thousands were killed, wounded, or captured, and the German Sixth Army was left dying in the rubble of Stalingrad. Poorly equipped and totally unprepared for the war, they were asked to fight. Drawing on first-hand accounts from veterans and civilians, as well as previously unpublished source material, this is the story of one of the greatest military disasters of World War II.