From the time that Stalin consolidated his position as the unquestioned leader of the Communist Party and the Soviet Union, in the late 1920s, all references to Lenin's testament were considered anti-Soviet agitation and punishable as such. The denial of the existence of Lenin's testament remained one of the cornerstones of historiography in the Soviet Union until Stalin's death on March 5, 1953. After Nikita Khrushchev's On the Cult of Personality and Its Consequences, at the 20th Congress of the Communist Party, in 1956, the document was finally published officially by the Soviet government.