The Yan'an Rectification Movement (), also known as Zhengfeng or Cheng Feng, was the first ideological mass movement initiated by the Chinese Communist Party (CCP), going from 1942 to 1945. The movement took place at the communist base at Yan'an, a remote and isolated mountainous area in northern Shaanxi, after the communists' Long March. Though it was during the Second Sino-Japanese War, the CCP was experiencing a time of relative peace when they could focus on internal affairs. The legacies of the Yan'an era proved fundamental to the subsequent history of the Chinese Communist Party, according to Kenneth Lieberthal. These included the consolidation of Mao Zedong's paramount role within the CCP, especially from 1942 to 1944, and the adoption of a party constitution that endorsed Marxist-Leninism and Mao Zedong Thought as guiding ideologies. This move formalised Mao's deviation from the Moscow party line and the importance of Mao's alleged 'adaptation of communism to the conditions of China'. The Rectification Campaign was successful in either convincing or coercing the other leaders of the CCP to support Mao. Because the CCP had overcome great odds to grow and develop during this period, the methods employed in Yan'an were looked upon in reverence during Mao's later years. After the founding of the People's Republic of China in 1949, Mao repeatedly used some of the tactics that had been successful in Yan'an whenever he felt the need to monopolize political power. To a large extent, the Yan'an Rectification Campaign began with the "systematic remolding of human minds." More than 10,000 were killed in the "rectification" process, as the CCP made efforts to attack intellectuals and replace the culture of the May Fourth Movement with that of Communist culture. The rectification movement is regarded by many as the origin of Mao Zedong's cult of personality. Background In the 1930s the remote region of Yan'an had not experienced the same turmoil and hostilities as other mainland territories. Situated in northwest China, the area was also difficult to attack. CCP members mostly arrived there after the Long March (1934–1935). The area was known as a territory of camaraderie without corruption, though the Rectification Movement essentially changed everything. According to official CCP sources, the purpose of the Rectification Campaign was to give a basic grounding in the Marxist theory, and Leninist principles of party organization to the thousands of new members who had joined the CCP during its