|Water Margin character|
|Rank||94th, Level Star (地平星) of the 72 Earthly Fiends|
|Chief executioner of Liangshan|
|Origin||Prison warden and executioner|
|Hometown||Daming Prefecture (in present-day Handan, Hebei)|
|First appearance||Chapter 62|
Cai Fu is a fictional character in the Water Margin, one of the Four Great Classical Novels of Chinese literature. He ranks 94th of the 108 Liangshan heroes and 58th of the 72 Earthly Fiends. He is nicknamed "Iron Arm". He shares the same nickname as the fictionalised persona of Zhou Tong.
Cai Fu is from Daming Prefecture (in present-day Handan, Hebei). He has a younger brother named Cai Qing, who also works as a prison warden and executioner like him. He possesses great strength and conducts executions by beheading smoothly, and earns himself the nickname "Iron Arm".
Lu Junyi is arrested and imprisoned after he is betrayed by his adulterous wife and housekeeper Li Gu. Li Gu bribes the Cai brothers to kill Lu Junyi in prison. However, Chai Jin meets the brothers later and he bribes them to take good care of Lu Junyi, with an even larger sum of money. Cai Fu discusses with his brother and they decide to help Lu Junyi. Lu Junyi's life is spared and he is sentenced to exile on Shamen Island instead.
Li Gu bribes the guards escorting Lu Junyi into exile to finish him off along the way, but Lu's loyal servant Yan Qing saves him from death and kills the guards. Lu Junyi is captured again later and sentenced to death, with Cai Fu as the executioner. Cai Fu deliberately lags for a while before the execution as he intends to spare Lu Junyi's life. Just then, Shi Xiu appears and he storms the execution ground alone in an attempt to rescue Lu Junyi. However, Lu Junyi and Shi Xiu are not familiar with the roads in Daming Prefecture and they are captured later. Grand Secretary Liang Shijie is afraid that the outlaws from Liangshan Marsh might attack Daming Prefecture to save their comrade so he decides to keep Lu Junyi and Shi Xiu alive as hostages. The Cais are assigned to watch over the prisoners and they treat them well.
As Liang Shijie expected, the outlaws come to attack Daming Prefecture. Song Jiang sends some spies to infiltrate Daming Prefecture during the Lantern Festival. Chai Jin goes to find the Cai brothers and he succeeds in persuading them to open the prison gates and allow Lu Junyi and Shi Xiu to escape. At the same time, the outlaws stationed outside Daming Prefecture launch an offensive on the city and succeed in breaking through. Lu Junyi and Shi Xiu are rescued and the Cais follow the outlaws back to Liangshan in triumph.
Campaigns and death
Cai Fu becomes one of the chief executioners of Liangshan with his brother. He follows the heroes on their campaigns against the Liao invaders and rebel forces after they have been granted amnesty by the emperor. During the Fang La campaign, Cai Fu is critically wounded in the battle of Qingxi County and dies from his wounds after the battle.
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- Buck, Pearl. All Men are Brothers. Moyer Bell Ltd, 2006. ISBN 9781559213035.
- Zhang, Lin Ching. Biographies of Characters in Water Margin. Writers Publishing House, 2009. ISBN 978-7506344784.
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