Zhang Renyuan (張仁愿) (died 714), né Zhang Rendan (張仁亶), formally the Duke of Han (韓公), was a Chinese military general and politician during the Tang Dynasty and Wu Zetian's Zhou Dynasty, serving as a chancellor during the reigns of Wu Zetian's sons Emperor Zhongzong and Emperor Ruizong and grandson Emperor Shang Background It is not known when Zhang Renyuan, whose name was initially Zhang Rendan, was born. It is known that his family was from Hua Prefecture (華州, roughly modern Weinan, Shaanxi) and that his grandfather Zhang Deyan () was a prefectural prefect during early Tang Dynasty, but nothing is known about his father Zhang Rong () beside the name. During Wu Zetian's reign It was said that Zhang Rendan was talented in both civil and military matters when he was young, and early in Wu Zetian's Zhou Dynasty, he was made Dianzhong Shi Yushi (), a low-level imperial censor. Around this time, there was another censor, Guo Ba (), who submitted a report to Wu Zetian claiming that she was the incarnation of Maitreya Buddha, and there was another official, Zhang Jiafu, who instigated the civilian Wang Qingzhi () into submitting a petition asking that Wu Zetian make her nephew Wu Chengsi the Prince of Wei crown prince, instead of her son Li Dan, formerly emperor until he yielded the throne to her in 690. Zhang Rendan was asked to cosign both documents and refused to do so, and he became known for this. In 696, when Wu Zetian commissioned the chancellor Wang Xiaojie to attack Tufan, Zhang Rendan was made the auditor for the campaign. Zhang submitted a report on the failures of the campaign, and as a result Wang was removed from his office. Zhang was thereafter promoted in his censor rank to Shi Yushi (). In 697, another censor, Sun Chengjing () served as an auditor of the border defense forces during a campaign, and after he returned from the campaign, he submitted a number of drawings showing him fighting and prevailing in battle. Wu Zetian was initially amazed, stating, "How can a censor be this faithful?" and promoted him to be deputy chief censor in charge of reviewing central government affairs. She asked Zhang to review the rolls of Sun's subordinates to see who should be rewarded. Zhang interviewed Sun and asked him to describe the battles—and Sun could not, because, in reality, he did