According to Zhou Li, as early as the Zhou Dynasty, there was a thing called "Dantu", which was used to record the location of the food city of the monarch and his subjects. In the Western Han Dynasty, it was called "Dan Shu Tie Yue" and was invented by Emperor Gaozu Liu Bang. In 202 BC, after Liu Bang established the Dahan Dynasty, in order to commend outstanding officials and generals, he wrote the oath of the emperor and these heroes on iron coupons with vermilion to win over officials and control heroes.
In order to ensure the credibility of the Iron Deed of Dan Shu and prevent forgery, the iron deed was divided into two parts, half of which was put in the Golden Temple and hidden in the stone ancestral hall, and the other half was awarded to the minister. Xiao He, Cao Can, Shawn, Chen Ping, zhou bo, Fan Kuai and other founding heroes have all obtained the hard evidence of "Dan Shu". At this time, the iron deed mainly recorded the number of titles, fiefs and food cities. There is no such thing as exemption from death, and there is no guarantee that future generations will inherit the title smoothly. According to Sima Qian's records, there were 100 heroes in the early Han Dynasty. However, a hundred years later, only the descendants of five heroes inherited the marquis, and the rest were either killed or given titles.
During the Northern and Southern Dynasties, due to frequent wars, everyone was in a precarious position, and wealth and hereditary status were out of the question. Therefore, from this time on, the oath of Dan Shu iron coupon was added to the statement of avoiding death. According to historical records, in 476 AD, Feng Taihou of the Northern Wei Dynasty awarded iron coupons to his favorite eunuch many times, "promising to live forever". In 543 AD, the Eastern Wei and the Western Wei fought in Mangshan. In the melee, Wei Yu Wen Tai, who blended Chinese and Western cultures, was trapped and almost captured. Fortunately, he was saved by Li Mu, the Foreign Ministry. Yu Wentai praised him and gave Li Mu an iron book coupon. Maybe he doesn't think it's enough to show his advantage. He also wrote on the coupon that "ten deaths must be tolerated", which means that he is allowed to commit ten capital crimes without killing people. However, Li Mu didn't use it until his death.
In the Tang Dynasty, it became more and more common for officials who loved women to issue iron coupons, and the number of times the recipients were spared from death was indicated. In the early Tang dynasty, it was 1 and 2 times. For example, in Tang Gaozu, Pei Ji, Liu Wenjing and Li Shimin enjoyed two exemptions from the death penalty, while Sun Chang Shunde, Liu Hongji, Dou Cong, Chai Shao, Liu Shilong and Zhao Wenke enjoyed one exemption from the death penalty. Even so, Liu Wenjing and Zhao Wenke, who had the iron coupons of Dan Shu, were finally killed.
In the middle and late Tang Dynasty, the number of times that the iron coupons of Dan Shu were spared from death was as high as 9 times to 10 times, and even the descendants were spared from death. If Qian Liu will die nine times, his descendants will die three times; Han Jianshu died nine times, and his descendants died twice. Emperor Xuanzong of the Tang Dynasty once gave An Lushan a red book coupon, but ironically, it was the favorite of the champion who launched the Anshi Rebellion that almost subverted the Tang Dynasty. After the eight-year war subsided, in order to win over the old generals of the Anshi Rebellion, Emperor Xuanzong of the Tang Dynasty "gave iron coupons and vowed not to surrender". I didn't expect it to cause division in the buffer zone where future wars and disasters are linked.
In the Tang Dynasty, more than 100 people won hundreds of years of iron coupons. As a result, more than a quarter of them were killed and did not enjoy the privilege of exemption from death. In the late Tang Dynasty and the Five Dynasties, Li only issued three iron coupons, two of which were killed. It can be seen that it is the emperor's decision whether the iron coupon of Dan Shu can be saved from death.
In the third year of Wu Ming, Zhu Yuanzhang presented iron coupons for the little red book to founding heroes such as Li Wenzhong, Li Shanchang, Shengfeng, Geng Bingwen, Fu Youde, Xu Da and Tang He. Although the number of times to avoid death is greatly reduced, it at least shows that it is possible to avoid death. Wang Wei Xu Da lived three times at most, his son lived twice, most governors lived less than three times, and his descendants lived less than three times.
Take Li Shanchang as an example. Although he enjoyed the privilege of "saving two dead and saving his son from death", he was framed as a crime of rebellion and more than 70 people in his family were killed. At that time, Li Shanchang was already the first hero of Daming's founding. Even if he helped Hu rebellion succeed, he was still the first hero. Why do you want to rebel in your 70 s? After the Qing army entered the customs, the iron ticket of Dan Shu withdrew from the historical stage and was replaced by the yellow jacket and the iron hat king. At this time, ministers no longer pay attention to whether this thing can avoid death. After all, it doesn't depend entirely on what the emperor says.
It can be seen that the real purpose of the so-called Danshu Iron Voucher is just to record the merits and rewards of the minister. Whether death can be avoided depends on the situation. After all, the final interpretation right lies with the emperor. Therefore, it is more appropriate to regard the iron coupon of Dan Shu as the honorary certificate of the minister.