Li Jiji (李繼岌) (died May 28, 926), formally the Prince of Wei (魏王), nickname Hege (和哥), was an imperial prince of the Chinese Five Dynasties and Ten Kingdoms period state Later Tang. He was Later Tang's founder Emperor Zhuangzong of Later Tang (Li Cunxu)'s oldest son, and was commonly regarded at the time to be Emperor Zhuangzong's heir apparent. As such, he served as the titular commander of Later Tang's campaign to destroy its neighbor Former Shu, albeit with the major general Guo Chongtao in effective control. After Later Tang conquered Former Shu, however, under the command of his mother Empress Liu, Li Jiji killed Guo, leading to a chain reaction of mutinies that doomed Later Tang.
During Jin
It is not known for certain when Li Jiji was born. However, it is known that he was the oldest son of Li Cunxu, then the Prince of Jin. His birth date could further be confined by the historical assertion that his mother Lady Liu, who was Li Cunxu's concubine, was not his favorite initially — a Lady Hou, who had previously been the wife of Fu Daozhao (符道昭), a general of Jin's archrival Later Liang, whom he captured in a battle in 908 shortly after his succession (after the death of Li Jiji's grandfather Li Keyong), was — and it was not until Lady Liu gave birth to Li Jiji, whom Li Cunxu believed resembled him greatly, that she gained favor and became his favorite.
The first historical reference to Li Jiji was in 917 (although it is unclear whether the incident actually happened in 917 itself), when there was a time when Li Cunxu had him dance in the honor of the eunuch official Zhang Chengye, and Zhang gave him a gift to show thanks — and yet displeased Li Cunxu, who considered the gift as being too small in amount. (The dispute was resolved when Li Cunxu realized, at the urging of his mother (Li Jiji's grandmother) Lady Dowager Cao of Zhang's faithfulness by not expanding from the royal treasury.) In 922, when Li Cunxu met with a key ally, Wang Du the military governor of Yiwu Circuit (義武, headquartered in modern Baoding, Hebei), Wang proposed to give his daughter in marriage to Li Jiji, and Li Cunxu agreed. (Li Jiji himself was said to be "emasculated from an illness" in childhood and never had a son.)
During Later Tang
During Emperor Zhuangzong's reign as emperor
In 923, Li Cunxu, considering himself the legitimate successor to Tang Dynasty, declared himself emperor of a new Later Tang (as its Emperor Zhuangzong). For the time being, he had his capital at Xingtang (興唐, in modern Handan, Hebei), naming it the eastern capital, but also designated the old Jin capital Taiyuan as western capital and Zhending (真定, in modern Shijiazhuang, Hebei) as northern capital, giving Li Jiji the titles of the defender of Zhending and the director of Xingsheng Palace (興聖宮). However, Li Jiji appeared to remain with Emperor Zhuangzong and his army at that point and did not head to Zhending.
Later in the year, Emperor Zhuangzong was preparing a surprise attack against Later Liang's capital Daliang. Believing that success would mean total victory but that failure would mean total defeat (as the surprise attack was a desperate measure given that Later Tang was having difficulty supplying its army), he sent Lady Liu and Li Jiji back to Xingtang, and bade farewell to them, informing them that if he failed, they should gather all the family members at the Xingtang palace and commit suicide by setting fire to it. Shortly after, he defeated the Later Liang army under Wang Yanzhang and Zhang Hanjie (張漢傑), and then quickly descended on Daliang. Caught by surprise, the Later Liang emperor Zhu Zhen committed suicide, ending Later Liang. Later Liang territory came under Later Tang control, and shortly after, one of Later Liang's most senior officials, Zhang Quanyi, arrived at Daliang to pay homage to Emperor Zhuangzong. Emperor Zhuangzong, in order to show respect to Zhang, had both Li Jiji and his uncle (Emperor Zhuangzong's brother) Li Cunji (李存紀) treat Zhang with the ceremony due an older brother — indicating that, by that point, Emperor Zhuangzong must have had Li Jiji brought to Daliang. Shortly after, Emperor Zhuangzong made Li Jiji the defender of Xingtang, and gave him the honorary chancellor designation of Tong Zhongshu Menxia Pingzhangshi (同中書門下平章事), although it was not clear whether Li Jiji actually returned to Xingtang. Later that year, he also had Li Jiji treat another major general, Zhu Youqian (whom he granted a new name of Li Jilin), as an older brother.