Xu Jingzong (592 – September 20, 672[1]), courtesy name Yanzu, posthumously known as Duke Gong of Gaoyang, was a Chinese cartographer, historian, and politician who served as a chancellor in the Tang dynasty.
Emperor Wen was impressed with Xu Shanxin's profound sadness (rather than abject submission) at the fall of his state, and made him an official in his own administration.
Xu Jingzong himself was said to be knowledgeable of literature in his youth, and, after passing the imperial examination, was made a scribe at Huaiyang Commandery (淮陽, roughly modern Zhoukou, Henan).
In 643, he assisted the chancellor Fang Xuanling in editing and then submitting imperial histories for Emperors Gaozu's and Taizong's reigns and, for his contribution to the project, was created the Baron of Gaoyang, given an award of silk, and promoted to be the acting deputy head of the examination bureau of government (門下省, Menxia Sheng).
In 645, Emperor Taizong was on the campaign against Goguryeo when the chancellor Cen Wenben, who was in charge of the legislative bureau and writing his edicts, died suddenly.
[2] After Cen's sudden death, Emperor Taizong summoned Xu to the front and put him in charge of writing the edicts, and made him acting deputy head of the legislative bureau.
(Despite the victory, however, Emperor Taizong's campaign would eventually end in failure, as he was unable to capture Anshi (安市, in modern Anshan, Liaoning) against the fierce defenses by the Goguryeo general later known in Korean popular stories as Yang Manchun.)
Around this time, however, he was accused of improperly accepting an excessive amount of bride price to give his daughter in marriage to a son of Feng Ang (馮盎), a powerful regional official and chieftain of the local people in modern Guangdong, and, for this perceived impropriety was demoted to the post of prefect of Zheng Prefecture (roughly modern Zhengzhou, Henan).
In 657, following Empress Wu's directions, Xu and Li Yifu accused Han and Lai (who were still chancellors at this point but had basically lost power) of conspiring with Chu to rebel.
In 658, he was made Zhongshu Ling (中書令), the head of the legislative bureau and also a post considered for a chancellor; he was also promoted to the greater title of Duke of Gaoyang.
Emperor Gaozong, after some hesitation, agreed without once meeting with Zhangsun to get his side of the story, exiling him to Qian Prefecture (黔州, roughly modern southeastern Chongqing).
In fall 659, Emperor Gaozong further ordered Li Ji, Xu, Xing, Ren Yaxiang, and Lu Chengqing to investigate Zhangsun's plot again.
Also apparently at Xu's suggestion, Emperor Gaozong ordered the executions of Han and Empress Wang's maternal uncle, Liu Shi (who had also been exiled).
In 662, Emperor Gaozong made Xu an advisor to the new crown prince as well as de facto chancellor of the first class, while continuing to exercise actual authority over the legislative bureau.
Instead, Emperor Gaozong ordered further discussion, and at the suggestion of the minister of ceremonies, Yang Sijing (陽思敬), Xu was given the posthumous name of Gong (恭, reverent).