On June 22, 1941, more than 3 million German troops invade Russia in three parallel offensives, in what is the most powerful invasion force in history. Nineteen panzer divisions, 3,000 tanks, 2,500 aircraft, and 7,000 artillery pieces pour across a thousand-mile front as Hitler goes to war on a second front.

Despite the fact that Germany and Russia had signed a “pact” in 1939, each guaranteeing the other a specific region of influence without interference from the other, suspicion remained high. When the Soviet Union invaded Rumania in 1940, Hitler saw a threat to his Balkan oil supply. He immediately responded by moving two armored and 10 infantry divisions into Poland, posing a counterthreat to Russia. But what began as a defensive move turned into a plan for a German first-strike. Despite warnings from his advisers that Germany could not fight the war on two fronts (as Germany’s experience in World War I proved), Hitler became convinced that England was holding out against German assaults, refusing to surrender, because it had struck a secret deal with Russia. Fearing he would be “strangled” from the East and the West, he created, in December 1940, “Directive No. 21: Case Barbarossa”—the plan to invade and occupy the very nation he had actually asked to join the Axis only a month before.

On June 22, 1941, having postponed the invasion of Russia after Italy’s attack on Greece forced Hitler to bail out his struggling ally in order to keep the Allies from gaining a foothold in the Balkans, three German army groups struck Russia hard by surprise. The Russian army was larger than German intelligence had anticipated, but they were demobilized. Stalin had shrugged off warnings from his own advisers, even Winston Churchill himself, that a German attack was imminent. (Although Hitler had telegraphed his territorial designs on Russia as early as 1925–in his autobiography, Mein Kampf.) By the end of the first day of the invasion, the German air force had destroyed more than 1,000 Soviet aircraft. And despite the toughness of the Russian troops, and the number of tanks and other armaments at their disposal, the Red Army was disorganized, enabling the Germans to penetrate up to 300 miles into Russian territory within the next few days.

Exactly 129 years and one day before Operation Barbarossa, another “dictator” foreign to the country he controlled invaded Russia, making it all the way to the capital. But despite this early success, Napoleon would be escorted back to France—by Russian troops.