Between 1939 and 1941, Germany invaded and occupied Poland, Norway, Denmark, Netherlands, Belgium, Luxembourg, France, Greece, Yugoslavia, Austria and Italy. Italy began as an ally of Germany; however, after Italy surrendered to United States and British forces, Germany marched in and seized Rome.
When Germany began plans to invade Poland, Hitler signed a nonaggression pact with Joseph Stalin, leader of the Soviet Union. In this pact, the Soviet Union secretly accepted Germany's invasion and occupation of Poland. The Soviet Union even went on to invade Finland, and with threats of invasion took control of Lithuania, Estonia and Latvia. When Germany invaded Poland, France and Great Britain declared war. However, Germany continued to invade and occupy countries, including France. In September of 1940, Germany even attempted to invade Great Britain by repeatedly bombing London. Londoners called this air raid attack the Blitz. It claimed more than 40,000 lives, but Britain did not surrender. In 1941, the United States actively joined forces with Great Britain and France to eventually defeat Germany, Italy and Japan. Many Jews in these German-controlled countries suffered in concentration camps during the war. One difference in their experience with that of German Jews was the speed at which Germany isolated and relocated them into ghettos and shipped them off to camps, according to The Holocaust Explained.