When Emperor Wuzong declared a general campaign against him, he was defeated, and he was subsequently killed, along with his clan members, by his own officer Guo Yi (郭誼).
Most of them believed that, given that Tang was facing incursions from remnants of the Huigu Khanate (which had recently broken apart after attacks by the Xiajiasi), a reconciliatory stance should be taken toward Zhaoyi and that Liu Zhen should be allowed to take over.
Lead chancellor Li Deyu disagreed, pointing out that Zhaoyi was isolated, and that as long as three circuits traditionally in de facto independence from the imperial government—Weibo (魏博, headquartered in modern Handan, Hebei), then ruled by He Hongjing; Chengde (成德, headquartered in modern Shijiazhuang, Hebei), then ruled by Wang Yuankui; and Lulong (盧龍, headquartered in modern Beijing), then ruled by Zhang Zhongwu—did not support Liu Zhen, Liu Zhen could not stand against imperial forces.
[6] Emperor Wuzong agreed and sent the eunuchs Jie Chaozheng (解朝政) and Xue Shigan (薛士幹) to Zhaoyi to demand to see Liu Congjian, to force the issue.
Subsequently, Emperor Wuzong put Li Yanzuo (李彥佐) the military governor of Wuning Circuit (武寧, headquartered in modern Xuzhou, Jiangsu) in command of the Hezhong troops.
It was said that this move caught Zhaoyi by surprise, as in the past it had been expected that the imperial government would make further attempts at reconciliation before ordering a general campaign.
Meanwhile, Liu Zhen submitted a petition defending himself, proclaiming his faithfulness to the imperial government and claiming that he was only resisting because of his fear of Qiu Shiliang.
[6] With He Hongjing delaying the launch of his troops, Emperor Wuzong, at Li Deyu's suggestion, pressured He Hongjing by ordering Wang Zai the military governor of Zhongwu Circuit (忠武, headquartered in modern Xuchang, Henan) to join the campaign, targeting Ci Prefecture (磁州, in modern Handan)—and, in doing so, cutting through Weibo territory.
This order surprised He Hongjing, who was fearful of Wang Zai's entry into his territory, and therefore he tried to head off imperial pressure by launching his troops thereafter.
[6] Meanwhile, a substantial part of Wang Maoyuan's troops, under his officer Ma Ji (馬繼), were stationed at Kedou Camp (科斗寨, in modern Jincheng).
The siege failed when Yicheng Circuit (義成, headquartered in modern Anyang, Henan) troops arrived to aid Wang Maoyuan, however.
Also, Emperor Wuzong, with Liu Mian and Zhang Zhongwu having a poor relationship due to their conflicts stemming from the earlier campaign against Huigu remnants, Emperor Wuzong moved Liu Mian to Yicheng Circuit and made the former chancellor Li Shi the new military governor of Hedong.
Xue's contacts with Wang Zai were then discovered, and Liu Zhen summoned him back to Lu Prefecture and killed him, along with his family.
[6] Liu Zhen's hopes were raised, when, on Chinese New Year 844 (January 24[1]), soldiers that Li Shi was ordered to send to the front to reinforce the Hedong soldiers already attacking Zhaoyi, angry that they were forced to do so at New Year time and that they had not received what they felt were adequate rewards to do so, rebelled at Hedong's capital Taiyuan Municipality (太原) under the leadership of the officer Yang Bian (楊弁), forcing Li Shi to flee.
At Li Deyu's suggestion, Emperor Wuzong refused Wang Zai's suggestion of accepting Liu Zhen's surrender, and ordered the Hedong soldiers under the officer Wang Feng (王逢), as well as soldiers sent by Yiwu (義武, headquartered in modern Baoding, Hebei), Xuanwu (宣武, headquartered in modern Kaifeng, Henan), and Yanhai (兗海, headquartered in modern Jining, Shandong) Circuits to attack Yang, followed up by troops from Wang Yuankui's Chengde Circuit.
[6] After one of Liu Zhen's officers, Gao Wenduan (高文端), defected to the imperial forces, he offered several key tactics on attacking Zhaoyi, based on its geography, and further suggested trying to persuade another major Zhaoyi officer, Wang Zhao (王釗), who was then helping the defense of Min Prefecture, to defect as well.