Hou Junji - During Emperor Gaozu's Reign

During Emperor Gaozu's Reign

It is not known when Hou Junji was born, and little is known about his family background other than that he was from Bin Prefecture (豳州, roughly modern Xianyang, Shaanxi). It was said that he was pretentious and always wanted to appear impressive. He favored using bow and arrows, and while he never achieved greatness in archery, he became known for his fighting abilities. At a point early in the reign of Emperor Gaozu, who was then still trying to reunify China after the collapse of Sui Dynasty, Hou came to serve under Emperor Gaozu's son, the major general Li Shimin the Prince of Qin. While serving under Li Shimin, for his accomplishments, Hou was created the Viscount of Quanjiao. He also became a close associate of Li Shimin, often offering Li his strategies.

By 626, Li Shimin was locked in an intense rivalry with his older brother Li Jiancheng the Crown Prince, and he feared that Li Jiancheng would kill him. Hou, along with Li Shimin's brother-in-law Zhangsun Wuji, Zhangsun's uncle Gao Shilian, and the general Yuchi Jingde, advised Li Shimin to act first and ambush Li Jiancheng and another brother who supported Li Jiancheng, Li Yuanji the Prince of Qi. Li Shimin agreed, and in 626 ambushed Li Jiancheng and Li Yuanji, killing them. During the subsequent battles between Li Shimin's forces and Li Jiancheng's and Li Yuanji's forces, Hou led Li Shimin's forces. When the dust had settled, Li Shimin effectively forced Emperor Gaozu to make him the crown prince, and then yield the throne to him (as Emperor Taizong).