It is not known when Li Chongmei was born — although he was both described by historians as "young, but as intelligent and agile as an adult" and self-described as a "child" even as of his death year, suggesting that he was not yet of adult age at that point. It is not known who his mother was, including whether she was Li Congke's wife Lady Liu or not. He was Li Congke's second son.
During Li Congke's reign
In 934, Li Chongmei's father Li Congke overthrew his adoptive brother Li Conghou, who was then emperor, and took the throne himself. As Li Chongmei's older brother Li Chongji and sister Li Huiming were executed by Li Conghou during Li Congke's rebellion, Li Chongmei was effectively Li Congke's only son. Apparently shortly after Li Congke took the throne, he gave Li Chongmei the title of imperial guard general, and shortly after gave him the titles of military governor of Chengde Circuit, honorary chancellor designation of Tong Zhongshu Menxia Pingzhangshi, mayor of Henan Municipality, and commander of the imperial guards. His military governorship was later moved from Chengde to Tianxiong Circuit. In spring 936, Li Congke created Li Chongmei the Prince of Yong. Not long after, Li Chongmei's uncle, Shi Jingtangthe military governor of Hedong Circuit, rebelled with aid from the Khitan Empire. When the main Later Tang forces Li Congke sent to attack Shi, commanded by Zhang Jingda, was defeated and surrounded by the combined Khitan/Hedong forces, Li Congke's high-level officials were all pushing for him to personally lead the imperial army against Shi. Li Chongmei volunteered to go in his stead, stating: Li Congke, who was hesitant to face Shi, initially was inclined to grant Li Chongmei's request, but the chancellor Zhang Yanlang, Liu Yanhao, and the director of palace affairs Liu Yanlang were all urging Li Congke himself to go, and therefore he launched his army, but he advanced slowly, fearful of Shi. He left Li Chongmei in charge of Luoyang. As continued news of Later Tang defeats were arriving at Luoyang, the people in the city were panicking and trying to leave the city and hide in mountains and valleys nearby. The guards at the city gates were initially inclined to stop them. Li Chongmei, however, stated: He thus opened the gates and allowed the people to leave, which actually served to calm the people's hearts. Shortly after, Li Congke returned to Luoyang, trying to mount a defense there, but with Shi approaching Luoyang and his generals submitting to Shi in droves, Li Congke gathered his family members and a number of officers still loyal to him and prepared to commit suicide by fire at Xuanwu Tower. Empress Liu, however, also planned to burn down the entire palace complex. Li Chongmei persuaded her not to, stating to her, "The new Son of Heaven surely cannot sleep under open air. He would only, at a future time, expend the energy of the people to rebuild. How is it that we should die and leave the people to hate us?" Shortly after, Li Congke's family, including Empress Liu and Li Chongmei, committed suicide by fire.
