On May 16, 1966, the Central Committee of the ruling Chinese Communist Party issued what is now known as the "516" directive, launching the Great Proletarian Cultural Revolution (1966-1976). To mark the 50th anniversary, Zhang Min of RFA's Mandarin Service spoke to California State University historian Song Yongyi, who specializes in researching a period that is still dominated by the official verdict in universities in mainland China:
RFA: What was the significance of the 516 directive?
Song: This was an internal party document that played a decisive role in the Cultural Revolution. It was sent out to cadres at 13 different ranks throughout the party. At this point the Cultural Revolution expanded from just being an internal party struggle to a mass movement.
After the founding of the Revolutionary Committee, Mao Zedong gradually took over and the whole thing became a mass movement. We regard the 516 directive as the start, because it was then that the program was set out, and the theory put forward.
But of course, there was a process. You can't say that the People's Daily editorial dated June 1, 1966 calling on people to sweep away all monsters, and destroy the "Four Olds" was the start.
But it's a complex historical issue. Some people say the Cultural Revolution only lasted three years ... but some people even say that it began with the May Fourth movement  or the 1911 Revolution, and others say it started in 1949 [with the founding of the People's Republic of China]. But I don't think it's a critical issue.
RFA: It's now 50 years since the Cultural Revolution began. Would you most like to talk about that era, or about China as it is today?
Song: I have been studying the Cultural Revolution for a long time, but I am also interested in some of China's current political structures and their relationship to the Cultural Revolution. Of course, the party has talked a lot about the problems left over by the Cultural Revolution, such as the huge losses to the national economy ... it also created a hiatus in the entire education system. A more controversial issue is how many people died unnatural deaths or were implicated [as enemies of the people]. Ye Jianying has estimated that this was more than 100 million including family members and relatives [who were also tainted by association].
RFA: What about the political impact?
Song: I think today when we are looking at the way the state controls the media or ordinary Internet users, or publications, this sort of autocratic control, we can say that this is part of the legacy of the Cultural Revolution. I think it can be said that the party's autocratic control was at its peak during that period, so because of that we are very sensitive to it.
As long as China is still a despotic political system, these phenomena will exist. For example, the controls on personal freedom, freedom of speech, books and newspapers, and so on. But this has been consistent all along ... and will remain so for as long as the government is a dictatorship.
I am more focused on the transmission of power at the highest levels, the 'successor' issue, and in this regard it can be said that China inherited a major legacy from Mao Zedong.
We all know that the Communist Party regime is a totalitarian system. The party even refers to itself as 'the dictatorship of the proletariat'.
RFA: Why haven't many other communist countries had a Cultural Revolution?
Song: I think the answer is very simple; they didn't have a leader like Mao Zedong. They may have been dictatorships, but they were still more pragmatic.
Mao had ambitions to become a new leader of the international communist movement, but he failed, not only economically, as in the failure of the Great Leap Forward (1958-1961), but also at an ideological level, in his pursuit of the Chinese dream [of catching up with developed, western countries.]
RFA: Do you think China will ever have another Cultural Revolution?
Song: There were a lot of factors that were accidental, as well as having a leader like Mao Zedong, and they were also crucial factors. People often ask to what extent the Cultural Revolution was political, to what extent to do with economic factors, internal party struggles, and so on, but they ignore the personality and charisma of Mao Zedong.
He was the most dangerous kind of dictator; the kind whose head is filled with big dreams the whole time.
RFA: So you don't think we'll ever see another Mao Zedong emerge? He was a total one-off?
Song: I think it would be hard to have a second founding emperor of the Chinese Communist Party.
RFA: A lot of people have remarked that Xi Jinping is behaving in many ways today like Mao Zedong. Do you think he will continue to go in this direction?
Song: I think he has similar dreams at a personal level, but whether he can actually implement them is another matter. In terms of the political structure, the important thing is whether he wants to establish a dictatorship under a single person, rather than a collective system of leadership. Is he aiming for supreme leadership such as Mao had during the Cultural Revolution?
Reported by Zhang Min for RFA's Mandarin Service. Translated and edited by Luisetta Mudie.