On June 22, 1941, Germany launched the largest military invasion in history — 3.8 million troops across a 2,900-kilometer front. Stalin had been warned repeatedly. He refused to believe it.
Operation Barbarossa, launched June 22, 1941, was the largest military operation in history. Over 3.8 million Axis troops — German, Romanian, Finnish, Italian, Hungarian, and Slovak — crossed into the Soviet Union along a front nearly 2,900 kilometers wide. Nothing remotely comparable had ever been attempted. The stated goal was to conquer the western Soviet Union to the Ural Mountains within three to five months.
Stalin had received warnings from British intelligence, his own spies, and even German deserters that the attack was coming. He dismissed them as provocations designed to drag the Soviet Union into war. When the invasion began, the initial Soviet response was chaos — commanders weren't sure whether to fight back, fearing they'd be accused of provoking a conflict. The first hours of the war saw the Soviet Air Force nearly annihilated on the ground.
The early weeks were catastrophic for the Soviet Union. German forces advanced 500 kilometers in the first three weeks, encircling entire Soviet army groups. The Battle of Kiev alone resulted in over 600,000 Soviet soldiers captured — the largest encirclement in military history. By December, Germany had killed, wounded, or captured more than 4.5 million Soviet soldiers.
The invasion was driven by Nazi ideology as much as military strategy. Hitler's goal was not merely conquest but the destruction of 'Judeo-Bolshevism' and the creation of lebensraum — living space — for German settlers. Behind the advancing army came Einsatzgruppen, mobile killing units that murdered Jews, Soviet officials, and others deemed enemies of the Reich. Barbarossa was simultaneously a military campaign and the beginning of the Holocaust.
Germany's army was built for rapid maneuver warfare, not the grinding attritional campaign that developed. As autumn turned to winter and the front stabilized short of Moscow, German forces faced temperatures of minus 40 degrees Celsius without adequate winter clothing. Trucks wouldn't start. Grease froze in artillery breeches. The army that had conquered Western Europe in six weeks was stalling in the Russian snow.
On December 5, 1941, the Soviets launched a massive counteroffensive outside Moscow — just as Germany thought victory was imminent. It was the first time a German strategic offensive had been stopped and reversed. The war would continue for nearly four more years, eventually killing an estimated 27 million Soviet citizens. Barbarossa set in motion the most destructive conflict in human history.