Li Zhengji
Meanwhile, Tian's alliance with the other generals was disrupted by his actions. Xue Song, who controlled Zhaoyi Circuit (昭義, headquartered in Anyang, Henan) had died in 773 and was initially succeeded by his son Xue Ping, who however yielded then to Xue Song's brother Xue E. In spring 775, however, Tian induced Zhaoyi's officer Pei Zhiqing () to expel Xue E and submit to him. Tian thus captured Zhaoyi's capital prefecture Xiang Prefecture easily. He was then able to seize three more of Zhaoyi's six prefectures, while the imperial government retained the two other prefectures and merged it with the nearby Zelu Prefecture (澤潞, headquartered in modern Changzhi, Shanxi), maintaining the name of Zhaoyi for the merged circuit. Meanwhile, he also looked down at both Li Baochen and Li Zhengji. In or shortly before 775, there was an incident where Li Baozheng and Tian's son Tian Wei () were playing polo at Weibo, when an accidental collision between Li Baozheng's and Tian Wei's horses killed Tian Wei. Tian Chengsi, in anger, imprisoned Li Baozheng and sent a messenger to Li Baochen in protest. Li Baochen, wanting to be conciliatory, sent a cane back with Tian's messenger and allowed Tian to discipline Li Baozheng—but Tian, in anger over his son's death, caned Li Baozheng to death, causing Li Baochen to break off the alliance with Tian. He and Li Zhengji, who also felt slighted by Tian, submitted petitions to the imperial government asking to attack Tian, and Emperor Daizong agreed, launching troops from a number of circuits loyal to the imperial government, in addition to Li Baochen's and Li Zhengji's forces, to attack Tian. Li Baochen, Zhu Tao (whose brother Zhu Ci had killed Zhu Xicai in 772, submitted Lulong to Tang imperial authority, and went to Chang'an to serve as chancellor, leaving Zhu Tao in command of Lulong), and Xue Jianxun () the military governor of Taiyuan Circuit attacked Tian from the north, while Li Zhengji and Li Zhongchen the military governor of Huaixi Circuit (淮西, headquartered in modern Zhumadian, Henan) attacked Tian from the south. Initially, these joint forces were successful in their attacks against Tian, seizing Ci Prefecture (磁州, in modern Handan) from Tian, but Tian was subsequently able to persuade Li Zhengji to break off his attack, substantially weakening the joint forces. Meanwhile, Li Baochen was offended when an imperial eunuch, Ma Chengqian (), who had visited Li Baochen's army, was so dissatisfied with Li Baochen's gift to him that he threw it on the ground, and Tian was also able to use hoaxes to persuade Li Baochen that if he joined forces with Tian to attack Lulong, he would be successful. Li Baochen thus turned against Zhu Tao, launching a surprise attack on him, but was unable to kill Zhu Tao, effectively ending any hopes of the campaign against Tian and subsequently creating an enmity between the Chengde and Lulong Circuits. Tian subsequent ceded Cang Prefecture (滄州, in modern Cangzhou, Hebei) to LI Baochen, cementing the reformed alliance and increasing Li Baochen's holdings to seven prefectures. Meanwhile, though, Tian submitted humble letters of submission to Emperor Daizong, offering to visit the Tang capital Chang'an to pay respect to Emperor Daizong. Emperor Daizong agreed, but as soon as Emperor Daizong pardoned Tian, Tian refused to visit Chang'an, and Emperor Daizong did not press the issue. During the campaign, however, Tian also lost Ying Prefecture (瀛洲, in modern Cangzhou as well) to Zhu Tao.