In the warm predawn darkness of June 22, 1941, 3 million men waited along a front hundreds of miles long, stretching from the Baltic coast of Poland to the Balkans. Ahead of them in the darkness lay the Soviet Union, its border guarded by millions of Red Army troops echeloned deep throughout the huge spaces of Russia. This massive gathering of Wehrmacht soldiers from Adolf Hitler's Third Reich and his allied states – notably Hungary and Romania – stood poised to carry out Operation Barbarossa, Hitler's surprise attack against the country of his putative ally, Soviet dictator Joseph Stalin.

Of the Soviet generals, none played as crucial a role in the war as Georgy Konstantinovich Zhukov, one of the most highly decorated army officers in Russian military history. At critical stages during the Second World War, it seemed as if it was Zhukov alone who stood between Russian defeat and German victory. Zhukov was ultimately involved in all the major battles on the Eastern Front, including Moscow, Leningrad, Stalingrad, Kursk, Bagration, and the final assaults into Poland and Germany to capture Berlin.

Stalin came to depend on Zhukov’s ruthless military skills for victory, but in the cut-throat Soviet Union, that was always a double-edged sword, because it seemed that Stalin envied Zhukov and feared him as well. Zhukov, who could be as aggressive and blunt as Stalin, was one of the few people prepared to stand up to the Soviet dictator and argue with him, and as many Soviet politicians and generals learned to their detriment, going toe to toe with one of the most brutal leaders of the 20th century was a highly risky venture. However, the mutual understanding they forged as they confronted the Germans may have played the biggest role in Hitler’s demise.