A Polish town lies in ruins following the German invasion of Poland, which began on September 1, 1939. Photograph »

Invading German troops enter the town of Lodz. Poland, September 8, 1939. Photograph »

Invading German troops approach Bydgoszcz. Poland, September 18, 1939. Photograph »

German troops parade through Warsaw after the surrender of Poland. Warsaw, Poland, September 28-30, 1939. Photograph »

German troops arriving in Norway by ship prepare for landing during the German invasion of Norway. May 3, 1940. Photograph »

German troops disembarking in Norway. May 3, 1940. Photograph »

German troops and bombers on an improvised airfield during the battle for Norway, May 3, 1940. Photograph »

German forces during the military assault on Rotterdam during the Western Campaign. Rotterdam, the Netherlands, May 1940. Photograph »

Ruined buildings in a French town destroyed by German forces during the Western Campaign. France, May-June 1940. Photograph »

German troops during the invasion of Yugoslavia, which began on April 6, 1941. Photograph »

German Stuka dive-bombers fly over Yugoslavia during the German invasion of Yugoslavia, which began on April 6, 1941. Yugoslavia, ca. April 6, 1941. Photograph »

SS troops advance during the invasion of Greece. The invasion of the Balkans began in April 1941. Greece, wartime. Photograph »

German vehicles loaded on trains headed toward the eastern front to reinforce German forces during the invasion of the Soviet Union in 1941. Photograph »