Li Bian
In 937, Xu Zhigao, then regent, had Wu's emperor Yang Pu yield the throne to him, ending Wu and starting a new state of Southern Tang. While Xu Jingda's older brothers Xu Jingtong (whose name was then changed to Xu Jing) and Xu Jingsui were given princely titles later that year, Xu Jingda initially was not, but was only given the title of Duke of Shouyang. (The other older brother, Xu Jingqian, had died shortly before the state transition due to illness.) In 939, he, and the rest of his family, took the family name of Li, which was his father's birth name. (Xu Zhigao also took a new personal name and became known as Li Bian.) Li Jingda received a princely title shortly after — variously referred to as Prince of Xuancheng or Prince of Xin. As a result of the name change, a controversy developed over whether he could remain married to his wife Princess Li, as a marriage between two people of the same family name was disallowed under Chinese traditions against endogamy. Li Bian decreed that due to Li Decheng's great accomplishments, the marriage shall remain valid, and that the princess was to take on the new family name of Nanping (as her father Li Decheng carried the title of Prince of Nanping). Throughout the years, Li Bian, impressed by Li Jingda's open disposition, had considered making him the heir to the throne, and the chancellor Song Qiqiu had also often praised his talent. However, Li Bian hesitated, and eventually did not do so, because Li Jing was older. (Still, Li Jing was never created crown prince, although his title of Prince of Qi was ceremonially greater than any other prince's as it was a title that both Li Bian and his adoptive father Xu Wen, who was Li Bian's predecessor as regent, had carried (in Xu Wen's case, posthumously).)