In this episode we look at the reasons for Hitler's decision to invade the Soviet Union in June 1941. Why was it called Operation Barbarossa? The Germans put together a large army (of up to almost 4 million soldiers) and they employed a three-pronged invasion strategy. We look at the role of the Einsatzgruppen in executing part of the Nazi's Final Solution. Why did Operation Barbarossa come to a halt in July 1941? We discuss the Russian winter, but also consider the willpower of the Russian soldiers. Was this invasion Hitler's biggest mistake? Find us on twitter @WilliamHPalk or @C_duPlessis.