It was systematic error to which he admitted to his mistakes and stepped down at the lushan
Conference. I’m sure you knew that already though right?
Sure you've got your timeline right, comrade professor?
Lushan Conference - Wikipedia
"The Lushan Conference was a meeting of the top leaders of the Communist Party of China held between July and August 1959."
"The Lushan Conference marked a key point of departure in Mao's rule. Criticism of party actions and policies were now equated with criticism of Mao.
Mao's speech at Lushan was incredibly passionate and bellicose. He defended himself by saying that he, like all of the great writers, Confucius, Karl Marx, and Lenin had made mistakes and that focusing on them would not help the situation. Moreover, he insisted that not one commune had collapsed yet.
His personal victory over Peng Dehuai at the Lushan Conference gave Mao confidence and led him to proceed with the Cultural Revolution. More than 3 million officials within the party were indicted and, for the first time, "class struggle" was brought into the upper echelon of the Party apparatus."
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Cultural Revolution - Wikipedia.
"The Cultural Revolution, formally the Great Proletarian Cultural Revolution, was a violent sociopolitical purge movement in China from 1966 until 1976. Launched by Mao Zedong, Chairman of the Communist Party of China (CPC), its stated goal was to preserve Chinese communism by purging remnants of capitalist and traditional elements from Chinese society, and to re-impose Mao Zedong Thought (known outside China as Maoism) as the dominant ideology in the CPC."
"The Cultural Revolution damaged China's economy and traditional culture, with an estimated death toll ranging from hundreds of thousands to 20 million."