Germany invaded Poland on September 1, 1939, marking the beginning of World War II.

Operation Fall Gelb was the German offensive that led to the rapid defeat of France in 1940.

The Battle of Stalingrad, which lasted from July 1942 to February 1943, was a decisive victory for the Soviet Union and marked the turning point of the war on the Eastern Front.

Operation Overlord was the code name for the Allied invasion of Normandy on June 6, 1944.

The first atomic bomb, codenamed "Little Boy", was dropped on the Japanese city of Hiroshima on August 6, 1945.

The Battle of the Bulge was the last major German offensive of the war and was fought in the Ardennes Forest in Belgium, Luxembourg, and eastern France.

Switzerland maintained its neutrality throughout World War II, despite being surrounded by Axis and Allied powers.

Operation Pointblank was the Allied strategic bombing campaign against Germany during World War II, which aimed to cripple German industry and infrastructure.

The Soviet Union liberated Poland, Czechoslovakia, Hungary, and Romania from German occupation in 1945.

The United Nations was established in 1945 to promote peace and cooperation among nations and prevent future wars.

The Soviet Union suffered the highest number of casualties during World War II, with an estimated 27 million deaths.

The White Rose, Edelweiss Pirates, and Black Orchestra were all German resistance movements that opposed the Nazi regime during World War II.

Japan was the last country to surrender to the Allies in World War II, on September 2, 1945.

The Yalta Conference was held in February 1945 between the leaders of the United States, Great Britain, and the Soviet Union to discuss the postwar order.

The Nuremberg Trials were held in Nuremberg, Germany, after World War II to try Nazi leaders for war crimes and crimes against humanity.