Princess Taiping is domineering, and the minor judge finds her guilty.

Li Yuan Vast, with the surname C, was a great-grandfather of C Chon, who served as a general of Tunwei during the Sui Dynasty. His great-grandfather, Beng Chon, served as the general of Tunwei during the Sui Dynasty, and was very good at appeasing the local people and won the hearts of the scholars. After Li Yuan, the Tang emperor, rose to power, Beng Chon led his people to join Li Yuan and was named Duke of Yingguo and given the surname Li.

In his early years, Li Yuan Vast served in Yongzhou as a counsellor and handled a case in which the defendant was the powerful Princess Taiping.

Princess Taiping and the people for profit

Princess Taiping was the daughter of Wu Zetian, and it is written in history that she was a woman with a big heart and a lot of intrigue. Princess Taiping was beautiful, promiscuous and keen on power, and Wu Zetian often said that Princess Taiping was “really like me”. Wu favored the princess and often consulted with her on political matters.

After the reign of Emperor Rui Zong of Tang, Princess Taiping was so powerful that she was feared by all officials.

Princess Taiping had 5,000 cognacs. In ancient times, the monarchs rewarded their subjects with fiefs, which were rented and taxed as their salaries. Princess Taiping’s estates were located in the suburbs of Chang’an, almost all of them were good fields near rivers, and irrigation was very convenient. Although the Princess Taiping sitting on the rich, but does not know enough.

There was a temple by bubble water in the southeast of Chang’an city. The monastery has a field close to Princess Taiping’s field. The monks placed a mill close by, using water power to start the stone mill. Princess Taiping and the monastery competed for the mill, and the monks sued the Yongzhou Prefecture.

South Mountain can be moved and the judgment cannot be shaken

After a detailed investigation, Li Yuan Vast knew that Princess Taiping was in the wrong, so he awarded the mill to the monastery. When his superior, Dou Huaizhen, the governor of Yongzhou, learned of this, he was shocked and, fearing Princess Taiping’s power, ordered him to change the verdict.

Li Yuan-vast wrote on the back of the verdict a few big words: “The South Mountain can be moved, but the verdict cannot be shaken”, meaning that the South Mountain could be moved, but the verdict would never be shaken. He stood by the original verdict and faced the pressure from his superiors. This incident was later condensed into an idiom called “Nanshan Iron Case”.

In the early years of the Tang Emperor Xuanzong’s Kaiyuan reign, Li Yuanqi became the magistrate of Wannian County. He was promoted to the position of the young magistrate of Jingzhao prefecture because of the fairness of the taxes and duties in his area. At that time, the princes and nobles would set up water mills beside the river canals to water their good lands, disregarding the people’s farmland and blocking the flow of water for profit. Li Yuan Vast ordered that all the water mills be demolished so that the water could flow smoothly and irrigate the people’s fields. Because of his policy, the people’s farmland had a good harvest.

Later, Emperor Xuanzong of Tang valued his talent and appointed him as the prime minister. For many years, Li Yuan Vast was a government official, but all the rewards he received were distributed to his family and friends. Even when he was the prime minister, he was extremely frugal.

The case of the mill was not a sensation at the time. However, because Li Yuan Vast was facing the powerful Princess Taiping, who was scorned by all the officials, the case became famous in history.


The New Book of Tang – Biography of Princess Taiping (Volume 83)
The New Book of Tang – Biography of Li Yuan Vast, Volume 126
Old Book of Tang – Biography of Li Yuanwu, Vol. 98