Li Bian was an orphan who was adopted by the Wu prince Yang Xingmi. He was then adopted by Xu Wen, the Prime Minister of Wu and was renamed Xu Zhigao. Upon Xu Wen's death, he took over power in Wu, and was made a prince of Qi. In 937, he proclaimed himself emperor of a new dynasty Qi, known in historiography as "Xu Qi". In 940, he changed his name to Li Bian and renamed the state Tang. Thus, the Southern Tang began as an empire, however under Li Jing, after 959 and the defeat of the Southern Tang by the Later Zhou, it was no longer diplomatically possible to claim the title of emperor in facing other states, thus he assumed the title of king. The state was at first relatively large and prosperous compared to the other Ten States of that period. Li Bian's rule was comparatively stable and prosperous. Li Jing took over when his father Li Bian died in 943. , Nanjing , founder of Southern Tang dynasty The Southern Tang was able to expand its holdings far beyond those of its Wu Kingdom predecessor. It took advantage of a rebellion in the Empire of Min when the northwest revolted and set up the Kingdom of Yin. Min appealed for help, but instead of helping, the Southern Tang absorbed parts of the rebellious territory into its own. Then, by 945, the Southern Tang completed its conquest of the Min Kingdom and absorbed it into its own boundaries. As with the Min, the Southern Tang was able to take advantage of internal squabbles within Chu to expand its territory even further. The Southern Tang sent in an army in 951 and removed the ruling family to their own capital in Nanjing, and annexed the territory. However, Li Jing suffered a setback from the Later Zhou between 956 and 958, and ceded all of its land north of the Yangtze River. Li Jing became a vassal of the Later Zhou. The last ruler, Li Yu, took over the state upon the death of his father in 961. The Song dynasty had conquered the northern part of the state located in Huainan, and thus Li Yu reigned no longer as an emperor but as the Ruler of the State of Jiangnan. Li Yu managed to maintain a semi-independent status of vassal of the Song but had to finally surrender after fighting for almost a year in 975. He was taken to the Song capital in Kaifeng where he offered his formal surrender to the Song emperor in early 976.
Coinage
It is possible that Xu Zhigao cast a cash coin with the inscription Daqi Tongbao while the state still had its original name of Great Qi though the cash coins of preceding dynasties were still strong in circulation, under the reign of Li Jing cash coins were produced with the inscriptions Baoda Yuanbao, Yongtong Quanhuo, Datang Tongbao, and Tangguo Tongbao. The latter two series were produced as "matched coins" where the same inscription was used but different fonts of Chinese calligraphy were used simultaneously while these cash coins all retained the same sizes and weights. Under Li Yu cash coins were cast with the inscription Kaiyuan Tongbao was used in clerical and seal scripts and was based on a Tang dynasty era cash coin of the same inscription. The Southern Tang mint was also the first mint in Chinese history to issue vault protector coins, these special coins served like numismatic charms and were hung in the treasury's spirit hall for offerings to the gods of the Chinese pantheon, and Vault Protector coins would be hung with red silk and tassels for the Chinese God of Wealth.
