 After Li Yuan claimed Taiyuan's independence from Sui Dynasty, two of Li Yuan's sons, Li Jiancheng (李建成) and Li Yuanji (李元吉) were ordered to recruit soldiers in Taiyuan.However, due to their poor reputation, they could not recruit enough soldiers.Then, Li Yuanji advised Li Jiancheng to recruit under Li Shimin’s name because Li Shimin's reputation was much better than theirs.