Sun Chongjin was a native of the northern territory called Zhenwu (振武; around modern Hohhot, Inner Mongolia).
After the suppression of the rebel Huang Chao, Li Cunjin rose to a commissioner of Army of Righteous Sons (義兒軍使).
There he instilled strict measures on the surrendered Later Liang troops: anyone violating the regulations would be openly beheaded or dismembered, and this approach effectively prevented any possible unrest.
He was promoted to military governor of Zhenwu Command (振武軍; headquartered in modern Hohhot) after participating in the battles along the Yellow River.
[3] In 921, Zhang Wenli usurped the power in Zhao, eliciting a military response from Li Cunxu.