The Cultural Revolution (1966-1976) was the most destructive political movement in modern China. During that tumultuous ten-year period millions died as a direct consequence of political struggles and tens of millions were dislocated. Higher education was abandoned for the first five years. Leading experts in virtually all academic areas were deprived their rights of conducting research of their own interest. The promise of mathematical research during the first fifteen years of the newly created Communist China came to a halt, and then faded away. After briefly describing the status of mathematical research in Communist China before 1966, the speaker will provide a setting for the Cultural Revolution by showing a 10-minute documentary film. He will then take two leading Chinese mathematicians, Wu Wenjun, better known in the West as Wen-tsun Wu, and Gong Sheng, as examples, to discuss how the Cultural Revolution affected mathematicians’ personal lives and research. In order to show how politics and Marxist ideology determined mathematical research in mainland China during this period, the talk will also discuss Chinese translations of Karl Marx’s Mathematical Manuscripts and the nation-wide discussion of the Manuscripts.