Yang Pu (Chinese: 楊溥; 900 – January 21, 939), also known by his posthumous name as the Emperor Rui of Yang Wu (楊吳睿帝), was the last ruler of China's Yang Wu dynasty during the Five Dynasties and Ten Kingdoms period, and the only one that claimed the title of emperor. During his reign, the state was in effective control of the regents Xu Wen and Xu Wen's adopted son and successor Xu Zhigao (Li Bian). In 938, Xu Zhigao forced Yang Pu to yield the throne to him. Xu Zhigao then established the Southern Tang dynasty.
Yang Pu was born in 900, during the reign of Emperor Zhaozong of Tang, as the fourth son of the major late-Tang warlord Yang Xingmi the military governor (Jiedushi) of Huainan Circuit (淮南, headquartered in modern Yangzhou, Jiangsu), whose domain would become Wu eventually. His mother was Yang Xingmi's concubine Lady Wang. In 919, during the reign of his older brother Yang Longyan (King Xuan, Yang Xingmi's second son, who in turn succeeded another older brother, Yang Wo (Prince Wei of Hongnong)), Yang Pu was created the Duke of Danyang.
In 920, Yang Longyan fell ill, and the regent Xu Wen, who was effectively the ruler of the Wu government, arrived at the capital Jiangdu (江都, i.e., modern Yangzhou) to discuss with the officials there (including his adopted son, the junior regent Xu Zhigao) how to deal with the situation. Some of Xu Wen's followers encouraged him to take the throne himself. Xu, however, disavowing any such intent, proclaimed that he would surely find another son of the Yangs to succeed Yang Longyan. However, as he had long been apprehensive about Yang Xingmi's third son Yang Meng the Duke of Lujiang, who had long lamented Xu Wen's hold on the Wu governance, he did not wish to have Yang Meng succeed Yang Longyan. Instead, he issued an order in Yang Longyan's name, summoning Yang Pu to Jiangdu to serve as regent and moving Yang Meng to serve as the military prefect of Shu Prefecture (舒州, in modern Huangshan, Anhui). Yang Longyan died shortly after, and Yang Pu took the throne as King of Wu. He honored his mother Lady Wang as queen dowager.
In 921, Yang Pu, at Xu Wen's urging, formally sacrificed to heaven and earth, signifying his claim to the Mandate of Heaven. (Other officials tried to dissuade Xu, pointing out the high expenses of sacrificing to heaven and earth during Tang Dynasty, but Xu pointed out that Tang's ceremonies were overly wasteful and that proper ceremonies could be carried out without incurring the same high expenses that Tang expended.)
In 923, Wu's nominal ally Later Tang's emperor Emperor Zhuangzong (Li Cunxu), in his campaign against their joint enemy Later Liang, had just captured the strategically important city of Yun Prefecture (鄆州, in modern Tai'an, Shandong), and he personally wrote to Yang Pu, asking for the two states to jointly attack Later Liang. However, by this point, Wu was beginning to see Later Tang as a threat as well, and Xu considered sending a fleet north, and using it to aid whichever side prevailed. The official Yan Keqiu pointed out that he would have no good excuse not to commit to a position if Later Liang then requested aid as well, and so Xu did not launch the fleet.
Later in the year, Emperor Zhuangzong, in a surprise attack, captured the Later Liang capital Daliang. Later Liang's emperor Zhu Zhen committed suicide before the city fell, ending Later Liang, and Later Tang took over Later Liang's territory. Xu, in fear of what the Later Tang emperor might do next, blamed Yan for dissuading him from sending the fleet, but Yan pointed out that Emperor Zhuangzong had become arrogant in his victory and was not ruling his state well, predicting that within a few years his state would be in turmoil. Meanwhile, Later Tang's emissary to Wu initially delivered an edict from Emperor Zhuangzong, but Wu, not viewing itself as a Later Tang subject, refused to accept it. Emperor Zhuangzong rewrote his communication as a letter (thus showing equality between the states), but slightly displayed superiority by addressing the letter, "The letter from the Emperor of the Great Tang to the Lord of Wu." Yang Pu responded, also with a letter (thus also showing equality) but also showed deference by addressing the letter, "The respectful letter from the Lord of the Great Wu to the Emperor of the Great Tang." Shortly after, he also sent the official Lu Ping (盧蘋) as an emissary to Later Tang. Upon Lu's return, he confirmed Yan's observations – that Emperor Zhuangzong was wasting his time on tours and games, and was stingy with his funds, not willing to dispense them to soldiers, and thus causing discontent.
While Xu was in firm control of the Wu governance, in 924 Yang Pu was able to show some measure of sovereignty. At that time, there was an occasion when went to the port of Baisha (白沙, in modern Yangzhou) to review the fleet, and he changed Baisha's name to Yingluan Base (迎鑾, "Base that Welcomed the Emperor's Train"). Xu, who was then stationed at Jinling with Xu Zhigao at Jiangdu overseeing the government on his behalf, came to pay homage to him, and Yang Pu used this chance to complain about Xu's associate Zhai Qian (翟虔), whom Xu had put in control of the palace, as Zhai had put much restrictions on the King's movements and was spying on the King's moves. (Yang initiated the complaint by intentionally referring to rain (雨, yu) as "water" (水, shui), as Zhai's father's name was Zhai Yu, and Yang claimed that he, even as sovereign, felt so intimidated by Zhai that he had to observe naming taboo for Zhai's father.) Xu, realizing Yang's complaint, bowed and offered to put Zhai to death, but Yang stated that that was unnecessary but that an exile would be sufficient, so Xu exiled Zhai to Fu Prefecture (撫州, in modern Fuzhou, Jiangxi).
In 925, Qian Liu, the king of Wu's southeastern neighbor Wuyue (formally a vassal of Later Tang's), sent an emissary to Wu to inform Wu that he had been created the King of Wuyue by Emperor Zhuangzong. Wu, under the rationale that Wuyue was having designs on its own territory by accepting a title that included "Wu" in its name, refused to receive the emissary, and further cut off diplomatic and trade relations with Wuyue.
In 926, Emperor Zhuangzong was killed in a mutiny at the Later Tang capital Luoyang. His adoptive brother Li Siyuan, who led another mutiny and who shortly after arrived at Luoyang, declared himself emperor (as Emperor Mingzong) to succeed him. Yang sent an emissary to him to establish friendly relations (and offering fresh tea leaves as a tribute), but also internally declared a period for Emperor Zhuangzong.
In 927 there was an incident when the senior general Chai Zaiyong (柴再用) came to pay homage to the emperor, but was wearing his armor – which was inappropriate, and he was indicted by an imperial censor. Chai, however, citing his battlefield accomplishments, refused to accept the punishment. However, Xu Zhigao then tried to restore discipline by intentionally "accidentally" intruding into the palace, and then immediately withdrawing and submitting a petition asking to be punished for this intrusion. Yang issued an edict declining any punishment, but Xu Zhigao insisted on being punished by being stripped of one month's salary. It was said that this move restored discipline among the Wu officials.
Meanwhile, as the years went by, Xu Wen's biological son Xu Zhixun was repeatedly trying to persuade Xu Wen to have him replace Xu Zhigao as the overseer of the Wu government, and Xu Wen's associates Yan and Xu Jie were advocating the same, but Xu Wen was hesitant because Xu Zhigao was filially pious and careful, and his concubine Lady Chen also argued against it, pointing out that Xu Zhigao had been a son to him ever since the time that he was of low position, and should not now be abandoned. However, by late 927 he had resolved to do so, so he was preparing to go to Jiangdu from Jinling to urge Yang Pu to declare himself as emperor, and then use that opportunity to reassign both Xu Zhixun and Xu Zhigao. As he was about to depart Jinling, however, he became ill, and so he sent Xu Zhixun in his stead. Xu Zhigao, hearing the news, prepared to resign and request the post of military governor of Zhennan Circuit (鎮南, headquartered in modern Nanchang, Jiangxi), but while Xu Zhixun was on the way, Xu Wen died. Xu Zhixun rushed back to Jinling to take care of the aftermaths of his father's death, and Xu Zhigao remained as junior regent. Yang posthumously created Xu Wen the Prince of Qi.