The Green Dragon Crescent Blade (青龍偃月刀, Mandarin: qīng lóng yǎn yuè dāo，Cantonese: ching¹ lung⁴ yim² yuet⁶ do¹) was a legendary weapon wielded by Guan Yu (關羽) in the historical novel Romance of the Three Kingdoms (三國演義). It is a guandao (關刀), a type of traditional Chinese weapon.
It is also sometimes referred to as the Frost Fair Blade (冷艷鋸, lěng yàn jù), from the idea that during a battle in the snow, the blade continuously had blood on it; the blood froze and made a layer of frost on the blade.
In the novel by Luo Guanzhong (羅貫中), the blade was forged by a local blacksmith using steel sponsored by Zhang Shiping (張世平), a merchant sympathetic to Liu Bei (劉備)'s cause. When Guan Yu met his end at the hands of Lü Meng (呂蒙) in 219, the blade was given to Pan Zhang (潘璋) by Sun Quan (孫權) for his role in capturing of Guan Yu. Later, when Guan Yu's son Guan Xing (關興) soon sought revenge on Pan Zhang, Pan Zhang was startled by a vision of Guan Yu's spirit and was killed by Guan Xing. Guan Xing took back the Green Dragon Crescent Blade and thus the blade was passed down from father to son.
Historical validity
It is highly questionable whether Guan Yu (關羽) actually wielded the Green Dragon (青龍刀) or whether it was merely part of the myths surrounding him, valid historical text from his time period made no mention of him or anyone wielding a similar weapon. Because the guandao (關刀) was known not to be widely used until the Song Dynasty (宋朝), there is some doubt as to whether the guandao existed during Guan Yu's time. The guandao may not have been very widely-used because it was both difficult to wield, because of its heavy weight (Guan Yu, reportedly, was able to wield it agilely with just one hand, while most people would have trouble using it effectively even with both hands), and difficult to forge. This causes many to believe that it existed after Guan Yu.
According to Romance of the Three Kingdoms (三國演義) Chapter 1 (第一回), the Green Dragon Crescent Blade (青龍偃月刀) was said to weigh 82 catties (斤, jīn). During the Eastern Han Dynasty (漢朝) and Three Kingdoms periods (三國時代), one catty was approximately 220 grams, so 82 catties would have been approximately 18.04 kilograms (39.7782 pounds). A weapon weighing about 100 pounds (48 kilograms) purported to be the Green Dragon Crescent Blade is on display at the Purple Cloud Temple in China today.
Rumoured origins
Legend says that Guan Yu (關羽) invented the guandao (關刀). He had it forged after he met Liu Bei (劉備) and Zhang Fei (張飛) but before he made the Oath of the Peach Garden (桃園三結義).
The story of the blade was that there was a blacksmith forging the blade when suddenly a green dragon (青龍) passed by. The dragon was cut up and the body became part of the pieces therefore making the dao a magical weapon.
In popular culture
The weapon appears in several video games made by Koei (コーエー), but under incorrectly translated names. For example, it is called "Black Dragon" in Kessen (決戦) 2. However in the Dynasty Warriors (真・三國無双, Shin Sangokumusou) series it is named Blue dragon. This is likely because qing (青) may also mean blue, or black.
In the anime and manga Ikki Tousen (一騎当千, Battle Vixens) and visual novel and anime Koihime Musō (恋姫†無双), this weapon is wielded by Kan'u Unchou (關羽 雲長), who is intended to be a representation of Guan Yu (關羽).
http://en.wikipedia.org/wiki/Green_Dragon_Crescent_Blade
http://en.wikisource.org/wiki/Romance_of_the_Three_Kingdoms/Chapter_1#13
http://en.wikipedia.org/wiki/Kanu_Unch%C5%8D
Mythological weapons | Three Kingdoms | Chinese mêlée weapons
