Li Cunxu carefully rebuilt the Former Jin state, using a series of conquests and alliances to take over most of the territory north of the Yellow River, before starting a lengthy campaign against Later Liang.

Li Cunxu himself lived only three years after the founding of the dynasty, having been killed during an officer's rebellion led by Guo Congqian (郭從謙) in 926.

His father was the late-Tang dynasty major warlord Li Keyong the military governor of Hedong Circuit (河東, headquartered in modern Taiyuan, Shanxi).

He advocated aiding Liu to stop Zhu's expansion, while at time helping Li Keyong gain a reputation for magnanimity.

He claimed to be the proper ruler for all of the former Tang realm, but Li Keyong, as well as Li Maozhen, Yang Wo the military governor of Huainan Circuit (淮南, headquartered in modern Yangzhou, Jiangsu), and Wang Jian the military governor of Xichuan Circuit (西川, headquartered in modern Chengdu, Sichuan), refused to recognize him as emperor, effectively becoming sovereigns of their own realms (Jin, Qi, Hongnong, and Former Shu, respectively).

As described by the Song dynasty historian Sima Guang in the Zizhi Tongjian:[3] He ordered the prefectures and counties to recommend people who were good and talented; he also deposed the greedy and the cruel, relaxed the tax burden, comforted the weak and the poor, corrected injustice and excesses, such that the realm became well-governed.

Wang Rong, surprised by this turn of events, immediately sought aid from both Li Cunxu and Liu Shouguang.

In the aftermaths of the victory, Li Cunxu decided to advance further, and he briefly put Wei Prefecture (魏州, in modern Handan, Hebei), the capital of Later Liang's important Tianxiong Circuit (天雄), under siege.

However, apprehensive that a major Later Liang army under the command of the major general Yang Shihou was approaching, and more apprehensive that Liu Shouguang (who by this point was making noise about joining forces with him but demanding a leadership role in the army) might create trouble for him, he soon gave up the siege on Wei, ending the confrontation with Later Liang for the time being.

From this point on, Zhao and Yiwu became effectively independent polities, but in close alliance with Jin, all still using the Tang era name of Tianyou (天佑) to signify opposition against Later Liang.

Li Cunxu, in order to further encourage Liu into megalomania to be able to defeat him later, thereafter signed a joint petition with Wang Rong, Wang Chuzhi, as well as three other governors under his command—Li Sizhao, Zhou Dewei (whom he had made the military governor of Zhenwu Circuit (振武, headquartered in modern Datong)) and Song Yao (宋瑤) the defender of Tiande Circuit (天德, headquartered in modern Hohhot, Inner Mongolia)—offering Liu the title of Shangfu.

Zhu Quanzhong, while knowing that Liu was inflating himself, tried to keep him nominally in the fold by naming him the surveyor of the circuits north of the Yellow River.

[11] All of these honors offered to him, however, did not stop Liu from claiming the title he actually wanted, and in fall 911, he declared himself the emperor of a new state of Yan.

When Wang Chuzhi sought aid, Li Cunxu sent Zhou to rendezvous with the Zhao and Yiwu armies, to jointly attack Yan.

[11][13] Li Cunxu took him and his family, including his father Liu Rengong (whom he had put under house arrest) back to Taiyuan, and then executed them there.

The Tianxiong army was apprehensive and angry about the division, and therefore mutinied under the leadership of the officer Zhang Yan (張彥), taking He Delun hostage.

Around new year 919, the two armies met at Huliu Slope (胡柳陂, in modern Heze, Shandong), just south of the Yellow River.

During the initial rout, however, Li Cunxu took position on a hill and used it to counterattack, inflicting much losses against Later Liang, fighting the battle to an essential draw.

In late 920, when he remained for months at his vacation estate and refused to return to Zhao's capital Zhen Prefecture (鎮州), his military commander Li Ai (李藹) and eunuch Li Honggui (李弘規) felt compelled to mobilize soldiers to force him to return—and the soldiers, in the disturbance, killed Shi.

[12] Subsequently, the Khitan emperor invaded, enticed by Wang Yu's description of Chengde and Yiwu as rich lands that he could pillage.

Zhu Zhen was very pleased, and renamed the circuit to Kuangyi (匡義), commissioning Li Jitao as its military governor.

[2] Shortly after, in spring 923, Li Cunxu declared himself emperor of Tang—using the Tang name for his state to claim legitimate succession from Tang—at Wei Prefecture.

[2] At that time, though, the outlook for the new Later Tang state was not a positive one—as it was facing the reality of regular Khitan incursions that laid Lulong bare and Anyi's recent rebellion.

Wang quickly attacked and captured the border fort Desheng (德勝, in modern Puyang, Henan), intending to use it to cut off the supply line between Later Tang proper and Yun.

Meanwhile, Zhu also destroyed the Yellow River levee at Hua Prefecture (滑州, in modern Anyang, Henan), causing a flood area, believing that it would impede further Later Tang attacks.

He defeated them, capturing both Wang and Zhang Hanjie at Zhongdu (中都, in modern Jining, Shandong), and then headed directly toward the defenseless Daliang.

[15][17] This phenomenon was also observed as such by Wu's emissary to Later Tang, Lu Ping (盧蘋), and a former Later Liang warlord, Gao Jixing the military governor of Jingnan Circuit (荊南, headquartered in modern Jingzhou, Hubei, not the same Jingnan Circuit referred to earlier), who would eventually, after Li Cunxu's death, effectively become independent of Later Tang,[2] as well as Southern Han's emissary He Ci (何詞).

He decided to attack south and occupy Bian Prefecture (汴州, i.e., formerly Daliang), and Li Cunxu mobilized an army to try to intercept him.

[18] After he returned to Luoyang, the officer Guo Congqian (郭從謙) led a mutiny, and Li Cunxu tried to fight the mutineers.

[19] Li Cunxu's 4 ci poems were preserved in a Song dynasty book called Zun Qian Ji (尊前集; Collection of Respecting the Old).