Germany Invades Poland: World War II Begins

At 4:45 a.m. on September 1, 1939, the German battleship Schleswig-Holstein opened fire on the Polish military transit depot at Westerplatte, and 1.5 million Wehrmacht troops surged across the border from three directions. The assault followed a staged provocation at the Gleiwitz radio station the night before, where SS operatives dressed in Polish uniforms faked an attack to manufacture a pretext for invasion. Poland, with an army of roughly one million and an air force largely destroyed on its airfields within the first 48 hours, faced the most modern military machine the world had ever seen. Adolf Hitler had spent months preparing Fall Weiss (Case White), the operational plan that combined armor, infantry, and close air support in a devastating new form of warfare journalists would call Blitzkrieg. Panzer divisions punched through Polish defenses at multiple points while Stuka dive bombers terrorized both military positions and civilian refugees clogging the roads. Britain and France honored their defense treaties by declaring war on Germany two days later, but no meaningful military relief reached Poland. The Soviet Union invaded from the east on September 17, sealing Poland's fate under the secret protocols of the Molotov-Ribbentrop Pact signed just a week before the German attack. Warsaw held out until September 27, enduring relentless aerial bombardment that killed tens of thousands of civilians. The last organized Polish resistance ended on October 6, and Germany and the Soviet Union divided the country between them. The conquest of Poland killed approximately 66,000 Polish soldiers and 25,000 civilians in just five weeks. For the 3.3 million Polish Jews now trapped under Nazi and Soviet occupation, the invasion marked the beginning of a genocide that would claim the vast majority of their lives. The September Campaign shattered two decades of fragile European peace and launched a conflict that would eventually kill more than 70 million people worldwide.