Fa Zheng (176–220), courtesy name Xiaozhi, was a key adviser to the warlord Liu Bei in the late Eastern Han dynasty. Born in a family of high social status and of noble descent, Fa Zheng travelled to Yi Province (covering present-day Sichuan and Chongqing) in the late 190s and became a subordinate of Liu Zhang, the provincial governor. However, his feelings of alienation and perception of Liu Zhang as an incompetent governor eventually led him to betray Liu Zhang and defect to Liu Bei in 211. Between 211 and 214, Fa Zheng assisted Liu Bei in overcoming Liu Zhang and seizing control of Yi Province, and became one of Liu Bei's most trusted advisers. In 217, he urged Liu Bei to launch the Hanzhong Campaign to capture the strategic Hanzhong Commandery from a rival warlord, Cao Cao, but died a year after Liu emerged victorious in the campaign.