Excerpts from Books and Wikipedia
"The Cultural Revolution . . . was a sociopolitical movement in China from 1966 until 1976. Launched by Mao Zedong, then Chairman of the Communist Party of China, its stated goal was to preserve 'true' Communist ideology in the country by purging remnants of capitalist and traditional elements from Chinese society, and to re-impose Mao Zedong Thought (known outside China simply as Maoism) as the dominant ideology within the Party. The Revolution marked Mao's return to a position of power after the failures of his Great Leap Forward. The movement paralyzed China politically and negatively affected both the economy and society of the country to a significant degree." [Wikipedia] "Gang of Four: Radical clique led by Mao Zedong's wife, Jiang Qing, responsible for launching violent factional struggles during the Cultural Revolution. They were tried and convicted in 1980." [Fall and Rise of China Guidebook, p. 188] "Up to the mountains, down to the villages (shangshan, xiaxiang): The Maoist rustication movement of late 1968 that urged urban youths to resettle in the countryside to learn humility and discipline from peasants." [Fall and Rise of China Guidebook, p. 199]