On Sept. 1, 1939, one week after Nazi Germany and the Soviet Union signed a non-aggression pact, more than a million German troops--along with 50,000 Slovakian soldiers--invaded Poland. Two weeks later, a half-million Russian troops attacked Poland from the east. After years of vague rumblings, explicit threats and open conjecture about the likelihood of a global conflict--in Europe, the Pacific and beyond--the Second World War had begun.
In the weeks and months after the invasion, one of Adolf Hitler's personal photographer's, Hugo Jaeger, traveled extensively throughout the vanquished country, making color pictures of the chaos and destruction that the five-week battle left in its wake. Now, 75 years after the start of World War II, LIFE.com has published a series of Jaeger's pictures from Poland: haunting portraits of a country subjugated not by one enemy, but by several.
In Jaeger's photos, we see early, unsettling evidence of the violence, unprecedented in its scope, that would soon be visited upon scores of countries and countless people around the globe, from the streets of London and the forests of Belgium to the North African desert and the sun-scorched islands of the South Pacific.
Above: Refugees near Warsaw during the 1939 German invasion of Poland. (Sign reads, 'Danger Zone -- Do Not Proceed.')
Above: Captured Polish soldiers, 1939.
Above: Adolf Hitler views victory parade in Warsaw after the German invasion of Poland, 1939.
All photos: Hugo Jaeger--The LIFE Picture Collection/Getty Images