 It was said that he was skillful with his words and always acted appropriately, so much so that people were intimidated when they saw him.It was during Emperor Gaozu's reign that Emperor Gaozu changed his name from the original Yuanli to Dunli, although the reason was not stated in historical records.In 626, Emperor Gaozu's son Li Shimin the Prince of Qin, locked in an intense sibling rivalry with his older brother and Emperor Gaozu's oldest son, Li Jiancheng the Crown Prince, killed Li Jiancheng and another brother who supported Li Jiancheng, Li Yuanji the Prince of Qi at the Incident at Xuanwu Gate and effectively seized power.