The first Communist International meets in Moscow.

The Communist International (Comintern), also known as the Third International, was an international organization founded in 1919 that advocated world communism, headed by the Soviet Union. The Comintern resolved at its Second Congress to "struggle by all available means, including armed force, for the overthrow of the international bourgeoisie and the creation of an international Soviet republic as a transition stage to the complete abolition of the state". The Comintern was preceded by the 1916 dissolution of the Second International.

The Comintern held seven World Congresses in Moscow between 1919 and 1935. During that period, it also conducted thirteen Enlarged Plenums of its governing Executive Committee, which had much the same function as the somewhat larger and more grandiose Congresses. Joseph Stalin, leader of the Soviet Union, dissolved the Comintern in 1943 to avoid antagonizing his allies in the later years of World War II, the United States and the United Kingdom. It was succeeded by the 1947 Cominform.