 In 937, Xu Zhigao had Yang Pu yield the throne to him, ending Wu and starting Southern Tang.He created Princess Song empress.In 939, he changed his family name from the adoptive name of Xu to his birth name of Li (and also took on a new person name of Bian) and observed a mourning period for his birth parents where he and Empress Song wore mourning clothes and lived in a straw house for 54 days.