From a Marxist point of view the 1949 Chinese Revolution, in spite of its bureaucratic deformations, was the second most important event in human history after the Russian Revolution. It led to the abolition of landlordism and capitalism and the end of imperialist domination. Now, however, capitalism dominates in China. How did this happen? Here we present Part One of a document approved by this year’s world congress of the International Marxist Tendency which looks at events from the revolution up to the end of the Mao era.