Zhang Song
Around 211, when Liu Zhang received news that Cao Cao, the warlord who controlled the Han central government and the figurehead Emperor Xian, was planning to attack Zhang Lu, another warlord in the neighbouring Hanzhong Commandery, he became fearful that Cao Cao would attack Yi Province after defeating Zhang Lu. During this time, Zhang Song advised Liu Zhang to invite Liu Bei, a warlord based in the adjacent Jing Province, to lead his troops into Yi Province and help Liu Zhang deal with Zhang Lu. Liu Zhang heeded Zhang Song's advice and ordered his subordinate Fa Zheng to lead 4,000 men to welcome Liu Bei into Yi Province, in addition to presenting Liu Bei with several precious gifts.