Wikipedia:

The Great Proletarian Cultural Revolution, commonly known as the Cultural Revolution, was a social-political movement that took place in the People’s Republic of China from 1966 to 1976. Set into motion by Mao Zedong, then Chairman of the Communist Party of China, its stated goal was to enforce communism in the country by removing capitalist, traditional and cultural elements from Chinese society, and to impose Maoist orthodoxy within the Party. The revolution marked the return of Mao Zedong to a position of power after the failed Great Leap Forward. The movement paralyzed China politically and significantly affected the country economically and socially.

The Revolution was launched in May 1966. Mao alleged that bourgeois elements were infiltrating the government and society at large, aiming to restore capitalism. He insisted that these "revisionists" be removed through violent class struggle. China’s youth responded to Mao’s appeal by forming Red Guard groups around the country. The movement spread into the military, urban workers, and the Communist Party leadership itself. It resulted in widespread factional struggles in all walks of life. In the top leadership, it led to a mass purge of senior officials who were accused of taking a "capitalist road", most notably Liu Shaoqi and Deng Xiaoping. During the same period Mao’s personality cult grew to immense proportions.

Millions of people were persecuted in the violent factional struggles that ensued across the country, and suffered a wide range of abuses including public humiliation, arbitrary imprisonment, torture, sustained harassment, and seizure of property. A large segment of the population was forcibly displaced, most notably the transfer of urban youth to rural regions during the Down to the Countryside Movement. Historical relics and artifacts were destroyed. Cultural and religious sites were ransacked.

Source: Wikipedia, published under the GNU FDL. Retrieved 2013-08-24



About mass violence during the Cultural Revolution see: Song Yongyi, Chronology of Mass Killings during the Chinese Cultural Revolution (1966-1976), Online Encyclopedia of Mass Violence, [online], published on 25 August 2011, accessed 24 August 2013, URL : link, ISSN 1961-9898

Yongyi divides the purges and mass killings of the revolution into four time periods:

I. The Red Terror (August - December 1966)
II. All-round Civil War in China (January -  December 1967)
III. Killing for and by the New Organs of Power (1968-1971)
IV. Endless Killing (1972-1977)