Stalin's Great Purge, when millions were unjustly killed, was a campaign of political repression in the Soviet Union. It was orchestrated by Joseph Stalin from 1936 to 1939. It involved a large-scale purge of the Communist Party and government officials and the Red Army leadership, and repression of the peasants. There was widespread police surveillance, suspicion of "saboteurs", imprisonment, and arbitrary executions. In Russian historiography the period of the most intense purge, 1937–1938, is called Yezhovshchina (; literally, "the Yezhov regime"), after Nikolai Yezhov, the head of the Soviet secret police, the NKVD.