Zhang Song
In the early Jian'an era (196–220) of the reign of Emperor Xian, when famines broke out, Fa Zheng and his friend Meng Da travelled to Yi Province (covering present-day Sichuan and Chongqing) to join the provincial governor, Liu Zhang. Although Fa Zheng served as the Prefect () of Xindu County () and later as a Colonel Who Advises the Army () under Liu Zhang, he felt alienated because he neither held any important appointments nor made any significant achievements in his career under Liu Zhang. Besides, some of his fellows from Youfufeng, who had also moved to Yi Province, spoke ill of him in front of Liu Zhang. He maintained a close friendship with his colleague Zhang Song, who shared the same views as him about Liu Zhang being an incompetent and incapable governor.