During Sui Dynasty
Xu Jingzong was born in 592, during the reign of Emperor Wen of Sui. His ancestors had served as officials of the Southern Dynasties during the Southern and Northern Dynasties period for generations and claimed to be originally from Gaoyang Commandery before moving south of the Yangtze River in light of 's loss of the north. Xu Jingzong's father Xu Shanxin was serving as an emissary of Chen Shubao, the last emperor of Chen Dynasty, to Emperor Wen, whose Sui Dynasty then ruled the north, in 589, when Sui destroyed Chen to end the Southern and Northern Dynasties period and reunify China. Emperor Wen was impressed with Xu Shanxin's profound sadness 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 . He was soon made a low level official in the imperial administration of Emperor Wen's son . In 618, with virtually the entire Sui state engulfed by agrarian rebellions against Emperor Yang's rule, Xu Shanxin and Xu Jingzong were at Jiangdu with Emperor Yang and his other officials, when Emperor Yang was killed in a coup led by the general Yuwen Huaji. Yuwen was initially planning to spare Xu Shanxin, but after Xu Shanxin publicly refused to submit to him by dancing in his presence , Yuwen executed him. Xu Jingzong submitted to Yuwen and was spared. His exact travels after Emperor Yang's death were not clear, although it is known that he later served the rebel ruler Li Mi the Duke of Wei as a secretary , before eventually becoming a subject of Tang Dynasty, which emerged victorious from the civil wars near and after the end of Sui.
During Emperor Gaozu's reign
It is not clear what Xu Jingzong's activities were initially after becoming a subject of Tang Dynasty , but it is known that in 621, by which time Tang had prevailed over most, but not all, of its rivals in its campaign to reunify China after Sui's collapse, Xu was set to be sent to Lian Prefecture to serve as its prefect's chief advisor, when Emperor Gaozu's son the Prince of Qin, hearing that he was literarily talented, kept him in the capital to serve as a member of his literary staff at a mansion where he retained the best literary talent and served them with the best food and wine.
During Emperor Taizong's reign
In 634, eight years after Li Shimin had succeeded Emperor Gaozu as emperor , Xu Jingzong was made an imperial scholar responsible for editing imperial history, as well as a mid-level official at the legislative bureau of government . In 636, after Emperor Taizong's wife Empress Zhangsun died, the officials were observing a period of mourning and rotating in watching her casket, when Xu, seeing that the official taking that particular shift, Ouyang Xun, was exceedingly ugly in appearance, burst out in laughter, and was accused by the imperial censor for disrespect. He was demoted to the post of military assistant of the commandant at Hong Prefecture . Eventually, he was recalled to the capital to be in charge of imperial supplies and continued to also serve in the role of editing imperial histories. 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 . He was also soon made a junior advisor to Emperor Taizong's crown prince .
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. Emperor Taizong had left Li Zhi at Ding Prefecture , to be in charge of logistics, assisted by a number of officials led by the chancellor Gao Shilian, and Xu was a member of Li Zhi's staff there. 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. After Emperor Taizong had a major victory over the main Goguryeo forces, he had Xu draft an edict announcing the victory, and he praised Xu for the beauty of the language that Xu used. Later, at Xu's suggestion, staff members of Li Zhi's older brother and predecssor as crown prince, Li Chengqian , who had been long banned from civil service, had their eligibility restored.
During Emperor Gaozong's reign
In 649, Emperor Taizong died, and Li Zhi succeeded him . As part of the reshuffling of the imperial government, the minister of ceremonies, Yu Zhining was made chancellor, and Xu took over Yu's post as minister of ceremonies. 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 , 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 . In 652, he was recalled to the capital to serve as the minister of armory supplies, and in 655 was restored to his old post of minister of ceremonies.
Meanwhile, Emperor Gaozong's wife had lost her favors with the emperor, who now favored , and he wanted to depose Empress Wang and replace her with Consort Wu. The chancellors -- except -- were all opposed, with the harshest opposition coming from Chu Suiliang, Han Yuan, and Lai Ji. Xu became an ally of Consort Wu, along with the other officials Li Yifu, Cui Yixuan , and Yuan Gongyu . Xu tried to get the most powerful of the chancellors, Emperor Gaozong's uncle Zhangsun Wuji, to join their party as well, but Zhangsun, while not outwardly opposing Consort Wu's ascension, repeatedly showed implicit disapproval and refused to join Consort Wu's cause. He further repeatedly rebuked Xu, drawing Xu's resentment. Later in 655, despite severe opposition from Chu, Han, and Lai, Emperor Gaozong deposed Empress Wang and her ally and replaced Empress Wang with Consort Wu. During the controversy change of empresses, Xu publicly endorsed the move, stating that it was no one else's business if the emperor wanted to change empresses, and it was partly due to Xu's words that Emperor Gaozong's resolve was hardened, and he further demoted Chu out of the capital. In addition, once Empress Wang was deposed, Xu submitted a petition to have honors posthumously given to her father Wang Renyou rescinded.
In late 655, Xu also proposed that the crown prince Li Zhong be deposed and replaced with Empress Wu's oldest son Li Hong. In 656, Emperor Gaozong agreed and demoted Li Zhong to the title of Prince of Liang, creating Li Hong crown prince instead.
In 657, following Empress Wu's directions, Xu and Li Yifu accused Han and Lai of conspiring with Chu to rebel. Han, Lai, and Chu were all made prefects of distant prefectures and ordered to be permanently banished from the capital. Later that year, Xu was made ''Shizhong'' -- the head of the examination bureau and a post considered one for a chancellor. In 658, he was made ''Zhongshu Ling'' , 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.
By 659, Empress Wu, with her powers firm, began to seek further vengeance against those she felt had slighted her, and her prime target was Zhangsun and Yu. At that time, a man named Li Fengjie had accused the low level officials Wei Jifang and Li Chao of conspiracy, and Emperor Gaozong put Xu and Xin Maojiang in charge of the investigations. Xu used various interrogation tactics, including torture, to cause Zhangsun to be implicated, and Xu, citing the example of Yuwen Huaji, informed Emperor Gaozong that Zhangsun was about to rebel and should be immediately expelled from the capital. Emperor Gaozong, after some hesitation, agreed without once meeting with Zhangsun to get his side of the story, exiling him to Qian Prefecture . Xu then implicated Chu , Han, Lai, and Yu in the alleged plot as well. Chu's posts were posthumously removed, and Han, Lai, and Yu were removed from their posts. Chu's sons Chu Yanfu and Chu Yanchong were killed on their way to exile. Several of Zhangsun's relatives were also exiled. Later that year, Xu revised the rankings of various clans, promoting Empress Wu's Wu clan to the highest rank. In fall 659, Emperor Gaozong further ordered Li Ji, Xu, Xing, Ren Yaxiang, and Lu Chengqing to investigate Zhangsun's plot again. Xu, in response, sent Yuan to Qian Prefecture to force Zhangsun to commit suicide. Also apparently at Xu's suggestion, Emperor Gaozong ordered the executions of Han and Empress Wang's uncle .
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. Later that year, partially at Xu's instigation, fellow chancellor Xu Yushi was removed from his post, on the account that Xu Yushi had failed to report on his son Xu Ziran 's causing damage to private property, merely punishing Xu Ziran himself by caning him.
In 664, Emperor Gaozong, angry over Empress Wu's grip on power, secretly discussed with the chancellor Shangguan Yi the possibility of deposing her, but the discussions were discovered by Empress Wu, and Emperor Gaozong, in fear, blamed Shangguan for everything. At Empress Wu's instigation, Xu Jingzong submitted an accusation stating that Shangguan, who had previously served on Li Zhong's staff, was conspiring with Li Zhong and the eunuch Wang Fusheng , who had also previously served on Li Zhong's staff and who had reported to Emperor Gaozong that Empress Wu had engaged in witchcraft. Shangguan, his son Shangguan Tingzhi , and Wang were executed, while Li Zhong was forced to commit suicide.
In 670, at Xu's request, Emperor Gaozong allowed him to retire. He died in 672 and was buried near Emperor Taizong's tomb.
Criticism of Xu Jingzong and controversy over posthumous name
Traditional historians, both during Xu Jingzong's own times and in posterity, criticized Xu severely. In the aftermaths of his death, one of the imperial officials in charge for awarding posthumous names, Yuan Sigu , suggested giving him the unflattering posthumous name of Miu , stating that he deserved that posthumous name because he had given a daughter to Feng Ang's son in exchange for a large bride price, and because he had exiled his own son Xu Ang to the modern Guangdong region. Instead, Emperor Gaozong ordered further discussion, and at the suggestion of the minister of ceremonies, Yang Sijing , Xu was given the posthumous name of Gong .
Later historians' criticism of Xu were often on his twisting of history as a historian. They pointed out that he was resentful of Feng Deyi, who was chancellor during the reign of Emperor Gaozu and early in the reign of Emperor Taizong, because Feng had witnessed the coup at Jiangdu and had popularized Xu's disgrace in a couplet that stated: "When Yu Shiji was killed, Yu Shinan kneeled and asked to die in his stead; when Xu Shanxin was killed, Xu Jingzong danced to avoid death." Later, after Feng's death and Xu was in charge of writing history, he wrote a highly critical biography of Feng in order to pay Feng back. Other instances of Xu's twisting of history that were noted included:
* After marrying another daughter to the son of the general Qian Jiulong , again in exchange for a large bride price, he overly exaggerated Qian's contributions to Emperor Gaozu's success, ranking among with much greater contributors Liu Wenjing and Zhangsun Shunde .
* After having his son marry a daughter of Yuchi Baolin , he inflated the contributions of Yuchi Baolin's father Yuchi Jingde and hid Yuchi Jingde's faults, including attributing Emperor Taizong's poem ''Ode to a Powerful Phoenix'' , a tribute to Zhangsun Wuji, to be instead a tribute to Yuchi Jingde.
* The general Pang Xiaotai , whose contributions in Emperor Gaozong's campaign to conquer Goguryeo were minimal, was instead made out to be a major contributor during the campaign, after Pang gave Xu a major amount of treasure.
Generally, it was believed that Xu often altered the historical records of Emperors Gaozu's and Taizong's reigns based on personal likes and dislikes as well. It was, however, noted that Xu was a major contributor to many important imperially-commissioned works.