The fourth and last socialist international was founded by Leon Trotsky and his followers in 1938 in opposition to the Third International and the direction taken by the USSR under the leadership of Joseph Stalin. The Fourth International declared itself to be the true ideological successor of the original Comintern under Lenin, carrying on the banner of proletarian internationalism which had been abandoned by Stalin's Comintern. A variety of still active left-wing political organizations claim to be the contemporary successors of Trotsky's original Fourth International.