Germany was once the intellectual and cultural capital where Jews were well-integrated citizens. The rise of Nazism and Adolf Hitler led to the Holocaust, causing immense destruction. The 1920s and 1930s saw anti-Semitism and pogroms, but Jewish communities were prevalent in European society. The Nazis, led by Hitler, promoted extreme racist nationalism, targeting Jews. After gaining power due to social turmoil and economic collapse, Hitler established a dictatorship, passing racist laws like the Nuremberg Laws in 1935. The invasion of Poland in 1939 marked the start of World War II and the beginning of mass murder of Jews by the German military and police, resulting in roughly 2 million deaths within a few years. Jews were forced into ghettos to control and segregate them.