Zhang Guotao
In 1934 Chiang Kai-shek defeated the armies associated with Zhou Enlai and Mao Zedong, forcing them to undertake the Long March. Zhang Guotao considered attacking them, but Xu refused. Xu's refusal to attack Zhang's rivals may have contributed to Mao's acceptance of Xu under his own leadership later, after Zhang's 4th Front Army was eventually defeated by Chiang. Zhang was purged after returning to the areas around Yan'an controlled by Mao, but Xu was allowed to rejoin the Red Army under Mao's leadership after making an extensive self-criticism. His first position under Mao, as the deputy commander of the 129th division, was effectively a demotion.