Yao Chong himself started his civil service career serving as an attendant to Emperor Gaozong's son and crown prince Li Hong, and was known for being able to write quickly.
He later served as the food supply officer at Pu Prefecture (濮州, roughly modern Heze, Shandong).
He was then moved in his office five times and eventually became Xiaguan Langzhong (夏官郎中), a low-level official at the ministry of defense.
Less than a month later, she made him also the minister of defense (夏官尚書, Xiaguan Shangshu) and chancellor de facto again, with the greater designation of Tong Fengge Luantai Sanpin (同鳳閣鸞臺三品).
Around this time, Wu Zetian's lover Zhang Yizhi wanted to move 10 senior Buddhist monks from the capital Luoyang to a temple that he had built in Ding Prefecture (定州, roughly modern Baoding, Hebei).
Soon, Wu Zetian, while letting Yao remain chancellor, made him the commanding general of the army at Lingwu, apparently again contemplating a campaign against Eastern Tujue.
I am willing to be punished for this, if this is viewed as a crime.Huan and Zhang Jianzhi thereafter demoted Yao to be the prefect of Bo Prefecture (亳州, roughly modern Bozhou, Anhui).
In 710, Emperor Zhongzong died suddenly—a death that traditional historians believed to be a poisoning carried out by his wife Empress Wei and daughter Li Guo'er the Princess Anle so that Empress Wei, like Wu Zetian, could become "emperor" and Li Guo'er could become crown princess.
He and another chancellor, Song Jing, were said to be concentrating on ending the problematic policies of Emperor Zhongzong's reign, including reforming the civil service system and removing officials who had improperly received offices by bribing powerful people at court.
In 711, Song and Yao, trying to end to political uncertainty, suggested sending Li Chengqi and Li Shouli out of the capital Chang'an to serve as prefectural prefects, while sending Princess Taiping and her husband Wu Youji (Wu Zetian's nephew) to settle in the eastern capital Luoyang.
Emperor Ruizong accepted the suggestion except as to Princess Taiping's place of settlement (sending her to the closer Pu Prefecture (蒲州, roughly modern Yuncheng, Shanxi) rather than Luoyang).
He was then made the secretary general at Yang Prefecture (揚州, roughly modern Yangzhou, Jiangsu), and was said to have governed it so well that the people built a monument dedicated to him.
In winter 713, Emperor Xuanzong carried out a major review of troops at Xinfeng (新豐, in modern Xi'an, Shaanxi), during which, due to the ceremony not being properly organized as it was supposed to be, he removed and exiled the chancellor Guo Yuanzhen, who was also minister of defense.
The next day, Emperor Xuanzong summoned Yao to his presence and made him minister of defense and chancellor with the designation Tong Zhongshu Menxia Sanpin, and created him the Duke of Liang.
In 714, Yao, pointing out that veneration of Buddhist monks did nothing to save Later Zhao, Later Qin, Northern Qi, and Liang dynasty, suggested that Emperor Xuanzong order a thorough review of the ranks of Buddhist monks and nuns and force those who were not truly devout to return to civilian life and be subject to taxation and labors.
Yao and his fellow chancellor Lu Huaishen, meanwhile, also did much to try to eliminate the culture of the nobles exerting influence in civil service matters.
At Yao's insistence that that not happen, he only removed Wei as a chancellor and made him the minister of public works (工部尚書, Gongbu Shangshu).
Also that year, when there was a major locust infestation in central China, Yao advocated capturing and killing the locusts—a strategy that initially yielded no results, and Emperor Xuanzong considered abandoning it.
Ni Ruoshui (倪若水), the prefect of Bian Prefecture (汴州, roughly modern Kaifeng, Henan), resisted the orders, claiming that Yao's strategy was carried out by the Han-Zhao emperor Liu Cong and failed miserably, and that only if people in power enhanced their virtues could the locusts be eliminated; Ni went as far as refusing to have imperial censors enter Bian Prefecture to carry out the order.
Yao wrote a formal order to Ni, stating: Liu Chong was a false emperor, and he lacked virtues and thus could not suppress evil.
Around this time, Yao suffered a bout of malaria, and as he did not have a mansion in Chang'an, stayed at Wangji Temple (罔極寺).
He wrote a will to his sons that disapproved the possibility of a Buddhist or Taoist funeral, stating: Buddhism pursues cleanliness and mercy, but many foolish people seek blessings by copying sutras and building buddha statutes.
In recent years, the Wus and the Weis built temples and encouraged innumerable people to become monks and nuns, but this did not prevent those two clans from being destroyed.
Do not follow those unknowing foolish men and women, burning incense and reciting sutras to beg for supernatural blessings.