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

The Axis Powers were a military alliance between Nazi Germany, Italy, and Japan during World War II.

Great Britain declared war on Nazi Germany on September 3, 1939, two days after the invasion of Poland.

Operation Fall Gelb was the German military operation that resulted in the capture of Paris in June 1940.

France was the first country to be liberated from Nazi occupation during World War II, in August 1944.

Operation Overlord was the name of the Allied invasion of Normandy in June 1944.

The Battle of Midway is considered to be the turning point of the war in the Pacific, as it marked the end of Japanese naval dominance.

The Tehran Conference was held in Tehran in 1943 to discuss Allied strategy for the war.

The United States was the first country to drop an atomic bomb during World War II, on the Japanese cities of Hiroshima and Nagasaki in August 1945.

The Treaty of San Francisco was the treaty that formally ended World War II, signed in September 1951.

The Soviet Union experienced the greatest loss of life during World War II, with an estimated 27 million deaths.

The United Nations was created after World War II to promote international peace and security.

The United States emerged as the dominant superpower after World War II.

The Cold War was the conflict between the United States and the Soviet Union that lasted from the end of World War II until the collapse of the Soviet Union in 1991.

The Soviet Union was the first country to launch a satellite into space during the Cold War, with the launch of Sputnik 1 in 1957.