Iosif Vissarionovich Stalin was a Soviet politician and revolutionary who ruled the Soviet Union from 1922 until his death in 1953, holding the titles of General Secretary of the Communist Party of the Soviet Union from 1922 to 1952 and the nation's Premier from 1941 to 1953. Initially presiding over an oligarchic one-party system that governed by plurality, he ultimately became the de facto dictator of the Soviet Union by the 1930s. Ideologically committed to the Leninist interpretation of Marxism, Stalin helped to formalise these ideas as Marxism–Leninism; his ideology represented by his policies based on Marxism-Leninism is known as Stalinism. In 1939, Stalin was General Secretary of the Communist Party of the Soviet Union and Premier of the Soviet Union. He oversaw the signing of a non-aggression pact with Nazi Germany before invading eastern Poland. Wiki link