Joseph Stalin was the leader of the Soviet Union from the mid-1920s until his death in 1953. Holding the post of the General Secretary of the Central Committee of the Communist Party of the Soviet Union, he was effectively the dictator of the state. Under Stalin's rule the concept of "Socialism in One Country" became a central tenet of Soviet society, contrary to Leon Trotsky's view that socialism must be spread through continuous international revolutions. Benito Mussolini was an Italian politician, journalist, and leader of the National Fascist Party (Partito Nazionale Fascista; PNF), ruling the country as Prime Minister from 1922 to 1943. He ruled constitutionally until 1925, when he dropped all pretense of democracy and set up a legal dictatorship. Known as Il Duce (The Leader), Mussolini was the founder ofItalian Fascism.