It was spring half a century ago when the People's Republic of China witnessed what is still the biggest purge of intellectuals and free-minded people in the nation's history. The 'anti-rightist campaign', as it became known, was initiated by Mao Zedong to consolidate his grip on power, and so effectively terrorised the public and the intelligentsia that its consequences continue to reverberate today.
The real starting point for the campaign and the exact timing of Mao's decision to purge the country's thinkers are questions only Mao himself could answer. But one thing is certain - at least half a million intellectuals, writers, journalists, students and ordinary people, irrespective of party membership, were labelled rightists and condemned as 'enemies of class, socialism, the nation and its people'.
Mainland history textbooks put the start of the campaign at June 8, 1957, but in recent years a growing number of biographies and memoirs of witnesses to the purge indicate that Mao began preparing for it much earlier because of his pathological suspicion that China's intellectuals opposed him.
The best guess as to when the preparations began is sometime in 1956, when a convergence of international and domestic developments prompted Mao to orchestrate several well-planned manoeuvres to trick intellectuals into voicing criticism.
Beyond China's borders, Nikita Khrushchev denounced Stalin's cult of personality and Eastern Bloc countries, including Hungary, rose up against Soviet domination. These events are believed to have struck so much fear into Mao that he felt tough measures had to be taken to expose and purge reactionaries.
Inside China, collective industrial and agricultural reforms had largely been completed and Mao decided it was time to apply similar controls to the generally free-spirited and democratic-leaning intelligentsia.