Toward the end of the Eastern Han Dynasty(25-220), state power fell into Dong Zhuo's hand, a very cruel and manipulating person. Yuan Shao, the leader of an opposition force, led a punitive（惩罚性的） expedition to Luoyang, the capital. Dong Zhuo sent a very battlewise general named Hua Xiong to meet the expedition army. Hua killed several generals in run from Yuan Shao's side. Guan Yu volunteered to meet Hua Xiong, saying if he failed to kill him he would kill himself. At this, Cao Cao, in admiration, poured a cup of heated wine for Guan Yu for encouragement. But Guan said, "Keep the cup here until I come back." When Guan Yu returned with Hua Xiong's head, the wine in the cup was still warm. Dong Zhuo was alarmed at the news that his brave general Hua Xiong had been killed.

He dispatched Lv Bu with 150,000 troops to guard the Hulao Pass outside the capital. Yuan Shao sent eight armies to attack. When the two sides met, no generals from Yuan Shao's side seemed able to withstand Lv Bu, several generals had been killed by him. Zhang Fei charged Lv Bu, but after fifty rounds of fierce combats he still did not succeed. At the sight of his sworn brother Zhang Fei unable to gain an upper hand, Guan Yu lifted his crescent-moon shaped sword to join the battle. After thirty more rounds, their elder sworn brother, Liu Bei unsheathed（抽出鞘） his sword and charged up too. The three brothers closed in. This proved too much for Lv Bu, who feigned a lance attack and while one of the three dodged, ran back to Hulao Pass for his dear life.