The Soviet Union from 1922–1991, Nazi Germany from 1933–1945, Italy under Benito Mussolini from 1922–1943, and various Eastern Bloc states are some of the best-known examples of one-party states in history. Some one-party states are considered dictatorships and called a police state or a military dictatorship, if a secret police force or the military is used to keep a dictator in power through force.