Li Keyong was a fierce general in the late Tang Dynasty, and the Later Tang regime of the Five Dynasties and Ten Kingdoms period was founded by him. Li Keyong was exceptionally brave and skilled in battle, and his eldest son, Li Cunxu, began following him into combat at the age of eleven, truly a case of "a tiger father has no dog sons." At that time, after the father and son returned victorious, they entered the palace to pay respects to Emperor Zhaozong of Tang. Zhaozong greatly praised the young Li Cunxu and predicted that his future achievements would surpass those of his father, Li Keyong.
During the late Tang Dynasty, the political situation was turbulent, with warlords locked in conflict. Li Keyong controlled the Hedong region, while Zhu Wen held the Henan area, and the two sides were at daggers drawn, confronting each other fiercely. However, due to limited territory and insufficient troops, Li Keyong found himself at a disadvantage and often felt disheartened. Li Cunxu then advised him to be patient, conserve strength, and wait for the right opportunity. Li Keyong found this advice reasonable and promptly rallied himself.
In 908 AD, Li Keyong died of illness, and Li Cunxu inherited the title of Prince of Jin. Li Keyong's younger brother Li Kening attempted to seize the throne but was killed by his own nephew Li Cunxu. At that time, the Jin army and the Liang army were locked in a stalemate at Luzhou. Li Cunxu had just ascended to power, his foundation was still unstable, and he was also in a period of mourning, so no one expected him to lead a surprise attack. Zhu Wen's Liang army, caught completely off guard, was utterly routed. Upon hearing the news, Zhu Wen remarked, "One should have a son like Li Yazi!" Yazi was Li Cunxu's childhood nickname.
During Li Keyong's lifetime, many generals and soldiers had fought alongside him for years, and he treated them generously, even allowing them to act as they pleased. Li Cunxu suggested to his father that military discipline should be tightened, but his advice was not taken. After his father's death, Li Cunxu immediately began reorganizing the army, severely punishing those who disrupted military order and executing several generals as a warning to others. He established very strict military regulations: before encountering the enemy, cavalry were forbidden from riding their horses; after battle plans were set, infantry and cavalry formations could not be altered arbitrarily; if the army split into several units heading to assembly points, no unit was allowed to be late, or its members would be executed without mercy. Additionally, Li Cunxu personally wrote lyrics and composed music for military songs, and before every battle, the Hedong army soldiers would sing these songs loudly to boost morale. This series of military reforms proved highly effective, greatly enhancing the army's combat effectiveness.
Before long, Li Cunxu's reform measures expanded from military affairs to political and economic areas. He ordered the dismissal of corrupt local officials and instructed each prefecture and county to recommend virtuous talents for government positions. He overturned unjust verdicts, cracked down on banditry, and continuously reduced taxes so that the common people could live and work in peace. In this way, while enhancing the army's combat effectiveness, Li Cunxu stabilized the political situation, spurred economic development, and won popular support, laying a solid foundation for his later unification of the north.
After three years of intensive military preparation, Li Cunxu finally defeated the army personally led by Zhu Wen in 911 AD. Soon after, Li Cunxu led his troops to capture Youzhou and captured the father-son duo Liu Rengong and Liu Shouguang alive. Nine years later, the Liao army led by Emperor Taizu Yelü Abaoji also suffered defeat at Li Cunxu's hands. In 923 AD, the Later Liang established by Zhu Wen was destroyed by Li Cunxu. Li Cunxu finally unified the north, established the Later Tang Dynasty with Luoyang as its capital. As the saying goes, "preserving achievements is harder than building them," Li Cunxu, who was brave and skilled in battle on the battlefield, turned into a tyrannical and foolish ruler after becoming emperor, personally ruining the great empire he had painstakingly built.
After becoming emperor, Li Cunxu grew extremely suspicious and completely stopped trusting the ministers who had helped establish the Later Tang Dynasty. His empress was very greedy, obsessed with amassing wealth, and conspired with eunuchs to frame loyal court officials. Li Cunxu had been fond of opera since childhood, and after ascending the throne, he abandoned state affairs to spend his days singing and performing. He gave himself the stage name "Li Tianxia." Once, while performing on stage, he called out "Li Tianxia" twice. An actor heard this, stepped forward, slapped him twice, and said, "You called out 'Li Tianxia' twice, but there is only one ruler of the world—who is the other 'Li Tianxia'?" Instead of getting angry, Li Cunxu was pleased and ordered a reward for the actor. He deeply favored the actors, granting them privileges and allowing them free access to the imperial palace. Li Cunxu even appointed actors as officials, letting them interfere in state affairs. Court ministers were disregarded and often bullied by them. Li Cunxu also trusted eunuchs greatly, sending them to various regions as officials to monitor local generals and administrators.
In 926 AD, Li Cunxu, heeding the slanderous words of eunuchs, had the great general Guo Chongtao executed, while another general, Li Siyuan, narrowly escaped death. The soldiers could no longer endure this, and together they rallied behind Li Siyuan to launch a mutiny. Having lost all popular support, Li Cunxu had no means to resist and was ultimately struck by a stray arrow, dying tragically amidst the chaos of the rebel forces. Subsequently, Li Siyuan ascended the throne as emperor, historically known as Emperor Mingzong of the Later Tang Dynasty.