Excerpts from Books and Wikipedia
". . . some 8000 survivors of Mao's First Army arrived in Yenan in October 1935 and successfully established themselves in the remote region. . . . During the year it took his armies to cross China, Mao Zedong established himself as the undisputed leader of the communists, and his devious tactics and ruthless sidelining of rivals on the march, such as Zhou Enlai, Lin Bao, Liu Shao Shi, and Deng Xiaoping, set a pattern he would follow up for the rest of his and their lives." [Furtado: 1001 Days]