[2] In 192, Li Jue, Guo Si and other former followers of the warlord Dong Zhuo banded together and attacked the Han imperial capital, Chang'an, and seized control of the central government and the figurehead Emperor Xian.
During this time, Yang Feng and Song Guo (宋果), another of Li Jue's subordinates, plotted to assassinate their superior but failed and were forced to leave Chang'an.
After three months, Zhang Ji managed to persuade Li Jue and Guo Si to make peace, and allow Emperor Xian to return to the old imperial capital, Luoyang.
Just as they reached the vicinity of Xinfeng (新豐) and Baling (霸陵), Guo Si changed his mind and wanted to bring Emperor Xian to Mei County (郿縣) instead.
In anger, Yuan Shu ordered his general Zhang Xun (張勳), with Yang Feng and Han Xian as his subordinates, to lead troops to attack Lü Bu.
Lü Bu heeded Chen Gui's suggestion and managed to induce Yang Feng and Han Xian to turn against Yuan Shu.
Yang Feng and Han Xian then joined Lü Bu in attacking Yuan Shu's forces, led by Zhang Xun, and defeated the enemy.