Di Renjie was a very famous politician of the Tang Dynasty, serving as an official for many years under Wu Zetian's rule and deeply trusted by her.
Di Renjie was born into an official family and entered government service after achieving outstanding results in the imperial examinations. In 686 AD, he was appointed as the prefect of Ningzhou, located in present-day Zhengning and Ningxian areas of Gansu, a region where various ethnic groups lived together during the Tang Dynasty. Di Renjie adopted a strategy of "pacifying and harmonizing the barbarians and Han, ensuring internal and external peace, so that people could live in peace," using appeasement to foster harmony between ethnic minorities and Han residents. Under his governance, Ningzhou's economy developed, and the people enjoyed a happy life. The local populace was deeply grateful, erecting a stele to praise his virtues. When Imperial Censor Guo Han inspected Ningzhou, the road was packed with people praising Di Renjie. Upon returning to the capital, Guo Han reported Di Renjie's achievements to the throne, leading to Di Renjie's promotion to Vice Minister of Public Works and Imperial Inspector of Jiangnan. Upon arriving in Jiangnan, Di Renjie found that unauthorized ancestral temples were widespread, placing a heavy burden on the local people. He petitioned the court to demolish these temples. The court, finding his arguments reasonable, approved his request. Consequently, over 1,700 temples in Jiangnan were destroyed, and the local people rejoiced.
After this, Di Renjie's talents were fully utilized, and his reputation grew increasingly prominent. Empress Wu Zetian held him in high regard and appointed him as Vice Minister of Revenue and a Grand Councilor in the Phoenix and Secretariat Chancellery. Despite holding high office and a key position, Di Renjie did not become complacent; instead, he held himself to even stricter standards. One day, Wu Zetian said to him, "When you served as an official in the south, your governance was excellent, yet some still slandered you. Do you wish to know who those slanderers were?" Di Renjie replied, "If Your Majesty believes I have done something wrong, I will correct it; if Your Majesty thinks I am blameless, that is my good fortune. I have no desire to know who slandered me." This magnanimous and forgiving attitude of Di Renjie greatly impressed Wu Zetian.
Di Renjie was broad-minded and never jealous of the talented, and he often recommended capable individuals to Wu Zetian. She once said to him, "I hope to find a person worthy of serving as Prime Minister.
Di Renjie said: "Su Weidao and Li Qiao are both very talented, but they cannot be considered truly exceptional individuals. If Your Majesty wishes to find someone truly outstanding, then it must be Zhang Jianzhi, the Chief Historian of Jingzhou. His talents are extraordinary, and he is the most suitable candidate for the position of Prime Minister."
Wu Zetian felt that Di Renjie's words were very reasonable. However, she did not immediately promote Zhang Jianzhi to Prime Minister, but instead promoted him to Luochuan Sima.
A few days later, Wu Zetian again asked Di Renjie to recommend candidates for the position of Prime Minister. Di Renjie said, "The Zhang Jianzhi I recommended last time has not been appointed as Prime Minister by Your Majesty." Wu Zetian replied, "Hasn't he already been given an important post?"
Di Renjie said: "Your Majesty has promoted him to Luochuan Sima, which is indeed a significant appointment. However, I recommended him to Your Majesty as a candidate for Prime Minister."
Under Di Renjie's persistent insistence, Wu Zetian promoted Zhang Jianzhi to Vice Minister of the Ministry of Justice, and soon after elevated him to Prime Minister. After becoming Prime Minister, Zhang Jianzhi helped Wu Zetian govern the country in an orderly and efficient manner.
Wu Zetian's nephew, Wu Chengsi, was determined to have her appoint him as the crown prince. Believing that Di Renjie would surely obstruct his plan, he colluded with the ruthless official Lai Junchen to frame Di Renjie and several other court ministers on charges of treason, throwing them into prison.
According to the laws of the time, if someone immediately confessed to the crime of plotting rebellion during interrogation, they could avoid torture. Di Renjie knew that Lai Junchen was ruthless and merciless, and only by saving his own life first could he have the chance to expose their conspiracy. Therefore, when Lai Junchen interrogated him, he immediately admitted that he had indeed intended to rebel. Seeing Di Renjie confess unreservedly to the charge of rebellion, Lai Junchen was very pleased and had Di Renjie imprisoned without close surveillance. Di Renjie tore open his quilt, ripped off a piece of the cover, wrote down in detail how he had been wronged, placed it inside a cotton-padded jacket, and then asked the prison guard to deliver the jacket to his home. His son Di Guangyuan found the piece of quilt cover bearing the account of the injustice and then went to Empress Wu Zetian to lodge a complaint.
Empress Wu Zetian summoned Di Renjie and several other ministers who had been falsely accused of treason into the palace and asked, "Since you claim you are innocent, why did you confess to plotting rebellion?"
Di Renjie calmly replied, "If I hadn't confessed, I would have been beaten to death long ago."
Wu Zetian asked again: "Why write a death confession?" Di Renjie replied: "I never wrote a death confession."
Empress Wu Zetian sent someone to retrieve the "Letter of Thanks for Death," and after Di Renjie examined it, he told her that he had not written it. Wu Zetian ordered an investigation and discovered the letter was a forgery. Realizing that Di Renjie and the others had indeed been wrongfully accused, she released them all. By using his intelligence and resourcefulness, Di Renjie managed to save his own life.
Later, Wu Chengsi repeatedly sent people to request that Wu Zetian make him crown prince. Wu Zetian, unable to decide, sought Di Renjie's advice.
Di Renjie said, "If Your Majesty appoints your own son as crown prince, then after your death, you will be honored with ancestral sacrifices in the Imperial Temple by future generations. But if you appoint your nephew as crown prince, I have never heard of any emperor enshrining his aunt in the Imperial Temple!"
Wu Zetian said: "This is my family matter, do not interfere."
Di Renjie replied very seriously, "All within the four seas is Your Majesty's territory, and thus all within the four seas is Your Majesty's household affair. I am Your Majesty's minister, and helping Your Majesty govern the realm better is my duty. Therefore, how could I possibly refrain from intervening in this matter?"
After earnest and patient persuasion, Di Renjie finally convinced Empress Wu Zetian to appoint Li Xian, the Prince of Luling, as crown prince. In doing so, the Tang imperial clan regained control of the realm, and Di Renjie rendered a great service to the Tang dynasty. For this reason, later generations hailed him as the "Pillar of the Tang Court."
After Di Renjie grew old, Wu Zetian no longer addressed him by his given name but instead called him "State Elder." Di Renjie repeatedly requested to retire and return to his hometown, but Wu Zetian never granted his requests. Knowing that Di Renjie worked tirelessly day and night, she instructed the court officials, "Do not trouble the State Elder with trivial matters; only matters of military and national importance should be brought to him." In 700 AD, Di Renjie died of illness. Wu Zetian posthumously appointed him as Right Chancellor of the Ministry of Culture and bestowed upon him the posthumous title of Wenhui. After Emperor Zhongzong of Tang, Li Xian, ascended the throne, he posthumously awarded him the title of Minister of Works. When Emperor Ruizong of Tang later took the throne, he further enfeoffed him as Duke of Liang.