Xu Wen () (862New History of the Five Dynasties, vol. 61. – November 20, 927Zizhi Tongjian, vol. 276.Academia Sinica Chinese-Western Calendar Converter.), courtesy name Dunmei (), formally Prince Zhongwu of Qi (), later further posthumously honored Emperor Wu () with the temple name Yizu () by his adoptive son Xu Zhigao after Xu Zhigao founded the state of Southern Tang, was a major general and regent of the Chinese Five Dynasties and Ten Kingdoms period state Wu. He took over the reins of the Wu state (then also known as Hongnong) after assassinating, with his colleague Zhang Hao, Yang Wo, the first Prince of Hongnong, and then killing Zhang. Xu was in essence the decision-maker throughout the reign of Yang Wo's brother and successor Yang Longyan and the first part of the reign of Yang Longyan's brother and successor Yang Pu. After his death, Xu Zhigao inherited his position as regent, eventually seizing the Wu throne and establishing Southern Tang.
Background Xu Wen was born in 862, during the reign of Emperor Yizong of Tang. His family was from Qushan (朐山, in modern Lianyungang, Jiangsu). When he was young, he was a salt privateer. His parents' names were lost to history, although it is known that his mother was surnamed Zhou.Zizhi Tongjian, vol. 267. At some point, he became a soldier under Yang Xingmi, who was then the prefect of Lu Prefecture (廬州, in modern Hefei, Anhui).
Service under Yang Xingmi Xu Wen initially did not distinguish himself in Yang Xingmi's campaigns — as while there were 36 officers under Yang who were considered to have distinguished themselves, led by Liu Wei () and Tao Ya (), Xu was not among them. His first known act while serving under Yang was in 889, during Yang's lengthy struggle against Sun Ru for the control of Huainan Circuit (淮南, headquartered in modern Yangzhou, Jiangsu), when Yang captured Xuan Prefecture (宣州, in modern Xuancheng, Anhui) after a lengthy siege. It was said that the other officers all hunted for spoils in gold and silk, but only Xu found a food supply, and had porridge cooked and distributed to the hungry people of Xuan Prefecture.Zizhi Tongjian, vol. 258.
In 895, when Yang, who had by that point taken Huainan and was serving as its military governor (Jiedushi), captured Hao Prefecture (濠州, in modern Chuzhou, Anhui), the soldiers captured a seven-year-old child, whom Yang initially took into his household. However, Yang's oldest son Yang Wo disliked the child, and Yang decided to give the child to Xu; Xu named the child Xu ZhigaoZizhi Tongjian, vol. 260. and had his second wife Lady Li raise the child as hers.Spring and Autumn Annals of the Ten Kingdoms (十國春秋), vol. 13. As Xu Zhigao was said to be diligent and filially pious, Xu Wen loved him.
Xu first distinguished himself in Yang's eyes in 902 when Yang was planning a major campaign against Zhu Quanzhong the military governor of Xuanwu Circuit (宣武, headquartered in modern Kaifeng, Henan). During the planning, most officers advocated using large ships to ship food supplies for the army, but Xu opposed, pointing out that the canals that would be utilized had long been silted and would be difficult to pass; he instead advocating using small boats for easy passage. He was not listened to, but when subsequently, Yang's army was hampered by the failure for large ships to arrive with food supplies (while smaller supply ships were getting through) and forced to withdraw, Yang became impressed with Xu and decided to give him greater responsibilities.Zizhi Tongjian, vol. 263.
The first instance where Xu was recorded to have distinguished himself in battle was in 903, when Yang was facing rebellions by his subordinates Tian Jun the military governor of Ningguo Circuit (寧國, headquartered at Xuan Prefecture) and An Renyi () the military prefect of Run Prefecture (潤州, in modern Zhenjiang, Jiangsu). Yang initially sent Wang Maozhang to attack An at Run Prefecture, but Wang could not defeat An. He sent Xu to reinforce Wang's army, and Xu had his soldiers change into identical uniforms as Wang's. An, not knowing that reinforcements had arrived, had no reservations about reengaging Wang's army, and was defeated by Xu. (However, Run Prefecture did not fall at this time.) However, Xu's role became even more prominent when, later in the year, Yang received word that his brother-in-law Zhu Yanshou (the brother of his wife Lady Zhu) had agreed to join Tian's and An's rebellion and was set to rebel at Shou Prefecture (壽州, in modern Lu'an, Anhui).Zizhi Tongjian, vol. 264. Xu, advised by his guest Yan Keqiu, submitted a proposal to Yang to trick Zhu Yanshou by having Yang pretend to be blind, even before Lady Zhu, and then issuing an order to summon Zhu Yanshou back from Shou Prefecture under the pretense of entrusting the affairs of the circuit to him. Zhu Yanshou believed this to be true and returned to Huainan's capital Yang Prefecture (), where he was killed in an ambush that Yang had Xu lay for him. After Zhu's death, Yang made Xu one of his two guard commanders.
In 904, when Tai Meng () the governor (觀察使, Guanchashi) of Xuan Prefecture died, Yang Xingmi commissioned Yang Wo to be the governor of Xuan. Xu privately spoke with Yang Wo, stating:Zizhi Tongjian, vol. 265.
Yang Wo, believing Xu was advising him out of good faith, wept and thanked him. In 905, when Yang Xingmi became even more ill, he was set on summoning Yang Wo back from Xuan Prefecture and entrusting the affairs of the circuit to him. Yang Xingmi's secretary Zhou Yin (), however, citing Yang Wo's frivolousness, opposed, instead suggesting that Yang Xingmi entrust the circuit to Liu Wei with a promise from Liu to transfer it to another son of Yang Xingmi's. Xu and the other guard commander, Zhang Hao, however, opposed Zhou's proposal, pointing out that Yang had fought these years to leave the state to his family. When Yang Xingmi subsequently issued an order and ordered Zhou to dispatch it to Yang Wo, Zhou did not send it for some time; when Xu and Yan found Yang Xingmi's order still on Zhou's desk, they took it and had it delivered to Yang Wo, who subsequently returned to Yang Prefecture. Yang Xingmi subsequently died, and Yang Wo, with the title of Prince of Hongnong bestowed by Emperor Zhaozong's emissary Li Yan, took over the circuit.
Service under Yang Wo After Yang Wo annexed Zhennan Circuit (鎮南, headquartered in modern Nanchang, Jiangxi) in 906, he became increasingly arrogant and intolerant. He executed Zhou Yin, which caused fear to permeate among his staff members. Despite being still in the mourning period for Yang Xingmi, he spent his time, day and night, in feast and games. When Xu Wen and Zhang Hao tried to tearfully dissuade him from such behavior, he angrily stated to them, "If you believe that I am not capable enough, why do you not kill me and take over yourselves?" This caused them to be fearful as well. They thus planned to act against Yang Wo. They first sent three officers who commanded Yang Wo's personal army (which he brought back from Xuan Prefecture), Zhu Siqing (), Fan Sicong (), and Chen Fan () to join under the general Qin Pei () in Qin's operations to pacify Zhennan, and then sent an officer, Chen You () to execute them at Qin's camp under false charges of treason. When Yang Wo heard of this, he prepared to kill Xu and Zhang, but before he could act, they acted first. In spring 907, they took 200 guards under their command into the mansion, claiming to be carrying out bingjian (兵諫, i.e., "correction by force"). They executed a group of Yang Wo's close associates and then, while not physically acting against Yang Wo himself, effectively took control of the headquarters. If other officers disagreed with them, they found reasons to execute those officers.Zizhi Tongjian, vol. 266.
Later in 907, the powerful warlord Zhu Quanzhong the military governor of Xuanwu Circuit (宣武, headquartered in modern Kaifeng, Henan) forced Emperor Zhaozong's son and successor Emperor Ai to yield the throne to him, ending Tang and starting a new Later Liang with Zhu as its Emperor Taizu. Yang Wo, along with Li Keyong the Prince of Jin, Li Maozhen the Prince of Qi, and Wang Jian the Prince of Shu, did not recognize the new Later Liang emperor as emperor, and continued to use the Tang era name of Tianyou. Without a Tang emperor, however, he was in effect the ruler of a new state of Hongnong.
However, Xu and Zhang remained in effective control of the headquarters, and Yang Wo was hoping to, but unable to, eliminate them. They considered their own positions precarious, however, and they resolved to kill Yang Wo, divide the domain between themselves, and then submit to Later Liang. On June 9, 908, Zhang sent his subordinate Ji Xiang () into Yang Wo's mansion with soldiers under Zhang's command and killed him in his bedroom. (The reason why only Zhang's soldiers were used was that Xu pointed out that if they mixed soldiers, the soldiers may not cooperate with each other, and Zhang did not want to let Xu's soldiers conduct the assassination.) Zhang and Xu subsequently declared that Yang Wo had died of a sudden illness. When Zhang postured at taking over command of the domain, however, Yan Keqiu spoke up against it and subsequently produced a document, which he claimed to be from Yang Wo's mother Lady Dowager Shi, pleading for allegiance of the officers behind her younger son Yang Longyan. Zhang, rebuffed in his attempt to directly take over, acquiesced and allowed Yang Longyan to take the throne as the new Prince of Hongnong.
Service under Yang Longyan Subsequently, Zhang Hao tried to send Xu Wen out of the headquarters to be the governor of Zhexi Circuit (浙西, headquartered in modern Zhenjiang, Jiangsu), but Yan Keqiu persuaded Xu and Li Chengsi () the deputy military governor of Huainan that Zhang was intending to eliminate them and starting by sending Xu out of the capital; Xu thereafter found excuses to stay at Yang Prefecture. After Zhang then failed in an assassination attempt against Yan, Yan and Xu plotted to overthrow him. Xu subsequently got the officer Zhong Taizhang () to join the plot. On the night of June 18, Zhong took his soldiers and entered headquarters, killing Zhang and his close associates. Xu then blamed the assassination of Yang Wo on Zhang alone, and effectively took over as Yang Longyan's regent as the sole commander of the guards. He entrusted the military matters to Yan and the financial matters to Luo Zhixiang (), and it was said that both Yan and Luo were capable at their jobs, allowing Hongnong to be governed well. Xu himself was said to be calm, resolute, and frugal. While he was illiterate, when he had to rule on legal matters, he would have others read the legal papers to him before ruling on them with proper reasoning.
As of 909, Xu was also carrying the title of deputy commander of the Huainan army (行軍副使, Xingjun Fushi) when he, believing that Jinling was a key location to control the Yangtze River with a fleet, gave himself the additional title of prefect of Sheng Prefecture (昇州, i.e., Jinling) but sent Xu Zhigao there to actually take command of the fleet there. Later that year, when Wei Quanfeng the prefect of Fu Prefecture (撫州, in modern Fuzhou, Jiangxi), who had nominally submitted to both Hongnong and Later Liang, rose against Hongnong and claimed the title of military governor of Zhennan, Xu, at Yan's recommendation, sent Zhou Ben against Wei. Subsequently, Zhou defeated and captured Wei, allowing Hongnong to take Fu Prefecture under actual control.
In 910, the Hongong emissary to Qi and Jin (to announce Yang Wo's death), Wan Quangan (), returned to Yang Prefecture, and announced that Li Maozhen had, in his capacity as representative of the Tang emperor, bestowed the titles of Prince of Wu and Zhongshu Ling () on Yang Longyan. Yang Longyan accepted those titles; thereafter, Hongnong was known as Wu.