After he became a leader, Joseph Stalin began a five year plan course that was expected to convert the Soviet Union into an unstoppable superpower. His expansion plan was focused on the control that the government had over the economy, which included the enforced regimentation of Soviet agriculture. The government would do this by taking control of the farms. There were millions of farmers that declined to collaborate with Stalin's orders and those who rebelled were shot or banished as punishment. The enforced regimentation led to an extensive famine all across the Soviet Union, which killed millions. Stalin governed by terror and a totalitarian grip in order to overthrow anyone who could possibly cause a dispute about him. He broadened the management of the secret police, encourage citizens to spy on each other and had millions of people executed or sent to the Gulag system of enforced labor camps. In the late 1930s, Joseph began the Great Purge, this was a sequence of champagnes that were constructed to get rid of the Communist Party, the military and any other parts of the Soviet society that he would consider a threat. Stalin also constructed a cult of personality surrounding himself in the Soviet Union. Cities were renamed in his recognition. Soviet history books were rewritten in order to give him a more outstanding role in the revolution and mythologize other conditions of his life. He was the subject of laudatory works of art, literature and music, and his name even became a part of the Soviet national anthem. His government was also who regulated the Soviet Union.