Du Yan (died 8 November 628[1]), courtesy name Zhili, posthumously known as Duke Xiang of Anji, was a Chinese official who served as a chancellor during the reign of Emperor Taizong in the Tang dynasty.
It is not known when Du Yan was born, but it is known that he was from the Sui dynasty's capital commandery Jingzhao (京兆, i.e., Chang'an).
[2] In his youth, Du Yan had a good reputation for being talented in rhetoric, and he and a friend from the same commandery, Wei Fusi (韋福嗣), conversed between themselves and concluded that Emperor Wen of Sui favored people who had been hermits.
They therefore went into Mount Taibai (太白山, part of the Qinling Mountains), to try to gain reputations as hermits in order to benefit themselves later on in their careers.
Wang made Du Yan the minister of civil service affairs and trusted him greatly.
In 624, there was an incident where Li Jiancheng was discovered to have, against regulations, recruited additional soldiers for his guard corps.
Li Jiancheng's guard commander, Yang Wen'gan (楊文幹), in fear, rose in rebellion.
Emperor Taizong recalled Du Yan from exile, made him the imperial censor, and created him the Duke of Anji.
As the Old Book of Tang recorded, this was the conversation: At that time, Du was in multiple posts, but was not known for being honest.