As Later Liang Vassal
In spring 907, Zhu Quanzhong, who had had Emperor Zhaozong killed in 904 and replaced with Emperor Zhaozong's son Emperor Ai, had Emperor Ai yield the throne to him, ending Tang and establishing Later Liang Dynasty as its Emperor Taizu. Most local governors in the Tang empire recognized the new Later Liang emperor as their emperor, with the exceptions of Li Keyong the military governor of Hedong Circuit (河東, headquartered in modern Taiyuan, Shanxi), who carried the title of Prince of Jin; Li Maozhen the military governor of Fengxiang Circuit (鳳翔, headquartered in modern Baoji, Shaanxi), who carried the title of Prince of Qi; Yang Wo, who carried the title of Prince of Hongnong (each of whom claimed continued loyalty to the defunct Tang Dynasty but are generally viewed as independent states from this point on); and Wang Jian the military governor of Xichuan Circuit (西川, headquartered in modern Chengdu, Sichuan), who carried the title of Prince of Shu (and who soon thereafter declared his own state of Former Shu as its emperor). Qian Liu recognized the new Later Liang emperor as well, despite urgings by his staff member Luo Yin to join the other military governors in opposing Later Liang due to its usurpation of the Tang throne. Subsequently, Emperor Taizu created Qian the Prince of Wuyue and also made him the titular military governor of Huainan as well as Zhenhai and Zhendong, and this is traditionally viewed as the founding of the Wuyue state. However, despite Qian's status as a vassal to Later Liang, instead of using Emperor Taizu's Kaiping era name, he adopted an era name of his own (Tianbao), signifying a claim on his own sovereignty.
Late in 907, Hongnong forces attacked Xin Prefecture (信州, in modern Shangrao, Jiangxi), then-held by the independent warlord Wei Quanfeng's brother Wei Zaichang (危仔倡). Wei Zaichang sought aid from Wuyue, and Wuyue forces attacked Hongnong's Ganlu Base (甘露鎮, near Run Prefecture) in spring 908 to try to relieve the pressure on Xin. Later in the year, he further sent Wang Maozhang (whose name was then changed to Wang Jingren to observe naming taboo for Emperor Taizu's father Zhu Cheng (朱誠)) to Later Liang to submit a plan to attack Hongnong. (Wang would thereafter remain at Later Liang and serve as a Later Liang general.) In response, Hongnong (which by this point was ruled by Yang Wo's brother and successor Yang Longyan after Yang Wo was assassinated in 908) sent Zhou Ben and Lü Shizao to put Su Prefecture under siege; by 909, however, Wuyue forces had defeated Hongnong forces sieging Su, and Hongnong forces retreated. Meanwhile, at Qian's request, the Later Liang general Kou Yanqing (寇彥卿) was also attacking Hongnong, but after Kou was unable to make much headway, Kou withdrew.
Later in 909, Wei Quanfeng gathered the forces in his domain (Fu (撫州, in modern Fuzhou, Jiangxi), Xin, Yuan (袁州, in modern Yichun, Jiangxi), and Ji (吉州, in modern Ji'an, Jiangxi) Prefectures) and attacked Hongnong's Zhennan Circuit (鎮南, headquartered in modern Nanchang, Jiangxi), aided by Ma Yin the Prince of Chu. Hongnong sent Zhou to engage Wei, and Zhou defeated and captured him. Wei Zaichang initially agreed to submit to Hongnong, but when Hongnong sent the officer Zhang Jingsi (張景思) to replace Wei Zaichang, Wei Zaichang, in fear, fled to Wuyue. Qian gave Wei Zaichang the title of deputy military governor of Huainan and changed his surname from Wei to Yuan (元) (as Qian disliked "Wei," which meant "danger").
In winter 909, Qian, having heard that Gao Li (高澧) the prefect of Hu Prefecture was violent and cruel to his people, wanted to executed Gao. Gao, hearing this, rebelled and offered to submit to Wu (i.e., Hongnong, as Yang Longyan by now was using the title of Prince of Wu that his father Yang Xingmi held). Qian sent Qian Biao to attack him, while Wu sent Li Jian (李簡) to try to aid him. Gao's officers Sheng Shiyou (盛師友) and Shen Xingsi (沈行思) turned against him, and Gao fled to Wu, allowing Wuyue to retain Hu, which Qian Liu made Qian Biao the prefect of after personally touring it to try to calm the locale. Also around this time, Qian built a major seawall at the mouth of the Qiantang River and enlarged the Hang Prefecture city perimeter. It was said that after this Hang Prefecture became the richest prefecture in the southeast China.
In 912, Emperor Taizu was assassinated by his son Zhu Yougui the Prince of Ying, who took the throne. Zhu Yougui bestowed on Qian the special title of Shangfu (尚父, "imperial father"), a title that Qian appeared to keep even after Zhu Yougui was in turn killed in a counter-mutiny in 913 and succeeded by his brother Zhu Youzhen the Prince of Jun. Also in 913, Wu made two attempts to attack and capture Yijin, commanded by Li Tao (李濤) in one operation and Hua Qian (花虔) and Wo Xin (渦信) in the other. Qian Liu sent Qian Chuanguan and Qian Chuanliao to resist, and both times defeated Wu forces, capturing Li Tao, Hua, and Wo. He then sent Qian Chuanguan, Qian Chuanliao, and Qian Chuanying to attack Wu's Chang Prefecture. They, however, were defeated by Wu's regent Xu Wen.
In 916, Qian Liu sent the official Pi Guangye (皮光業) to submit tributes to Zhu Youzhen, taking the lengthy route (as was required by geopolitical situations) through the domain of Wang Shenzhi the Prince of Min, the independent warlord Tan Quanbo (譚全播, whose headquarters was at Qian Prefecture (虔州, in modern Ganzhou, Jiangxi), and Chu. Zhu Youzhen was greatly touched by this gesture and conferred on Qian the title of Generalissimo of All Circuits (諸道兵馬元帥, Zhudao Bingma Yuanshuai), and then in 917 modified the title to Generalissimo of All Forces in the Realm (天下兵馬元帥, Tianxia Bingma Yuanshuai), which would from this point on become a title traditionally held by Wuyue kings. Also in 916, Qian Liu's son Qian Chuanxiang (錢傳珦) entered into a marriage with a daughter of Wang Shenzhi, and thereafter Wuyue and Min had friendly relations.
In 918, Wu attacked Tan's domain, and Tan sought aid from Wuyue, Min, and Chu. Qian sent his son Qian Chuanqiu (錢傳球) to put Xin Prefecture under siege to try to relieve the pressure on Tan. However, Zhou Ben, who was then the prefect of Xin, pretended that he had more forces than he actually had, and Qian Chuanqiu withdrew. Subsequently, the Wu general Liu Xin (劉信) defeated and captured Tan and incorporated his domain into Wu territory. (This cut off the route that Qian used for paying tributes to Later Liang, and from this point on he was forced to use the sea route to do so.)
In 919, Qian launched a major attack on Wu, with Qian Chuanguan in command. The operation was initially highly successful, with Qian Chuanguan crushing the Wu fleet under the command of Peng Yanzhang (彭彥章) on the Yangtze River at Langshan (狼山, in modern Nantong, Jiangsu). In light of the victory, Qian Chuanguan attacked Chang Prefecture, but was defeated by Xu Wen at Wuxi (無錫, in modern Wuxi, Jiangsu), killing the Wuyue generals He Feng (何逢) and Wu Jian (吳建) and forcing Qian Chuanguan to flee. Xu Wen's assistant and adoptive son Xu Zhigao wanted to counterattack and seize Su Prefecture, but Xu Wen, interested in using this victory to force Wuyue into a peace arrangement, declined. Instead, he returned the Wuyue captives that he took. Qian Liu, in return, sought peace with Wu, ending the long-term intermittent warfare between Wu and Wuyue. However, even though Yang Longyan and Xu Wen both repeatedly wrote Qian to urge him to declare independence from Later Liang, Qian refused. However, he also took no action when Zhu Youzhen ordered him to attack Liu Yan, who controlled the modern Guangdong and Guangxi region and who had recently declared himself the emperor of a new state of Southern Han. Subsequently, in 920, Wu further returned Qian Yi, who had been captured in 904 and continuously held, to Wuyue, while Wuyue returned Li Tao to Wu. Also in 920, Qian Liu and Ma Yin entered into a marriage arrangement where Qian's son Qian Chuansu (錢傳璛) married a daughter of Ma's, to cement a relationship between Wuyue and Chu.
In 923, Zhu Youzhen sent his official Cui Xie to create Qian Liu the greater title of King of Wuyue, signifying the Later Liang emperor's recognition of Qian as a sovereign of his own state albeit as a Later Liang vassal. Qian thereafter began to take on styles that were similar to, but slightly lower status to, the Later Liang emperor, including referring to his residence as a palace, referring to his place of administration as a court, and referring to his orders as edicts. Thereafter, also, by the emperor's permission, in his submissions to Later Liang he no longer referred to himself as a military governor but as the King of Wuyue. He also established a government structure that was akin to the imperial government, with lesser titles. The Later Liang emperor's edicts also referred to him only as the King of Wuyue and no longer by his name, to show deference to him. Qian thereafter made Qian Chuanguan the acting military governor of Zhenhai and Zhendong.
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