Emperor Zhaozong of Tang
The first substantially datable historical reference to Yao was in 902, when then-reigning Emperor Zhaozong of Tang had been forcibly taken by powerful eunuchs, led by Han Quanhui and Zhang Yanhong (張彥弘), to Fengxiang Circuit (鳳翔, headquartered in modern Baoji, Shaanxi), then governed by the eunuchs' ally Li Maozhen, the military governor ("Jiedushi") of Fengxiang. At that time, both Yao and his friend Han Wo were serving as imperial scholars (翰林學士, "Hanlin Xueshi") and had accompanied Emperor Zhaozong to Fengxiang; subsequently, Li Maozhen's rival Zhu Quanzhong the military governor of Xuanwu Circuit (宣武, headquartered in modern Kaifeng, Henan) put Fengxiang Circuit's capital Fengxiang Municipality under siege. When the chancellor Wei Yifan was forced to leave the imperial government for some time because his mother had died, the eunuchs initially recommended that Yao become chancellor to replace Wei. Han Wo recommended that Yao decline the commission: