Liu Bei's "Paired Winding Swords" (雙股劍), Guan Yu's "Green Dragon Crescent Blade" (青龍偃月刀), Zhang Fei's "Eighteen chi Serpent Lance" (丈八蛇矛), Zhao Yun's "Blue Steel Sword" (青釭劍), Cao Cao's "Sword of Heaven" (倚天劍), Sun Jian's "Ancient Ingot Blade" (古錠刀), Cheng Pu's "Ironspine Serpent Lance" (鐵脊蛇矛), and Lü Bu's "Fangtianhua Ji" (方天畫戟), otherwise known as the "Sky Piercer" or "Sky Piercing Halberd". While these are completely fictional, the Records of the Three Kingdoms do mention weapons unique to individuals on at least two occasions: Dian Wei's double halberd which weighed 20 kg and Gongsun Zan's two-bladed spear. Single combat The Records of the Three Kingdoms and Annotations to Records of the Three Kingdoms contain two instances of single combat between generals. In 192, after Dong Zhuo had been murdered, Li Jue and Guo Si formed an army to oust Wang Yun and Lü Bu from Chang'an. When Guo Si approached the city from the north, Lü Bu opened the gate and offered to settle the matter by single combat. Guo Si agreed and engaged with Lü Bu, who pierced Guo Si with his lance. Guo Si's men came forth, saving their general, and both sides withdrew. Another instance of individual combat occurred between Taishi Ci, then serving under Liu Yao, and Sun Ce. Taishi Ci was on a mission accompanied by only a single horseman when he met Sun Ce, who had 13 other men with him. Taishi Ci charged at Sun Ce and the two sides clashed in single combat. Sun Ce pierced Taishi's horse and managed to grab hold of his halberd while Taishi removed Sun's helmet. When their respective reinforcements showed up, they disengaged and the duel came to an end. Combat between generals and officers during battle is also mentioned by the Records. In 197 Yan Xing, an officer of Han Sui, engaged with Ma Chao and nearly killed him when his spear broke and pierced Ma Chao's neck. In 200 Yan Liang, a general of Yuan Shao, was slain by Guan Yu, then serving under Cao Cao, during the Battle of Boma. In 214 Zhang Liao charged Sun Quan's army with only 800 men and reportedly killed ten soldiers and two officers. He then broke through the enemy ramparts and challenged Sun Quan to a duel, to which he declined. Three Kingdoms Cao Wei Cao Wei was founded by Cao Pi in 220 and was usurped by