After the Xuanwu Gate, Li Shimin ascended to the throne, but the remnants of the Sui Dynasty and eighteen anti King left the military forces in the north desert make trouble, harm the people. Luo Tong, process Tieniu, Qin Huaiyu and a number of young adult, Luo Tong won the coach, led the Tang army battle, the way north desert. The Bohai Liao and Tang in the attack, Cheng Yaojin in command, Longmen County in the recruiting, Xue Rengui tears don't Liu Jin went to the army, army, Xue Rengui was Maogong, when an army cook, but he did not give up, with a body ability, Li repeated military exploits, finally got Cheng Yaojin recognition, Cheng Yaojin was recommended as the vanguard generals, Xue Rengui led the Tang army crushed the Bohai liao. Liu Jinhua in cold kiln in waiting for her husband ten years after, Xue Rengui said, don't forget the wife, Hui Long door with his wife and children. At the same time, Li Shimin in Wei Zheng, sun loudly princes assisted, good governance, created a flourishing.