"We should be modest and prudent, guard against arrogance and rashness, and serve the Chinese people’s heart and soul"——a quotation from Mao Zedong on a family photo taken in the 1970s.

At a factory in 1977, workers hold a banner reading "Expose and criticize the towering crimes committed by the Gang of Four on a full scale".

The Gang of Four was the name given to a leftist political faction comprised of four Chinese Communist Party officials. They came to prominence during the Cultural Revolution (1966-76) and were subsequently charged with a series of treasonous crimes. Members included Jiang Qing, Mao Zedong's last wife and leading figure of the group, and her close associates Zhang Chunqiao, Yao Wenyuan, and Wang Hongwen.