Prior to that, he had already been ruling Weibo Circuit (魏博, headquartered in modern Handan, Hebei) in de facto independence from the Tang imperial government as its military governor (Jiedushi), having succeeded his uncle Tian Chengsi in 779.
His father died early, and his mother remarried a soldier from Pinglu Circuit (平盧, then headquartered in modern Chaoyang, Liaoning).
Subsequently, as the army that his stepfather belonged to abandoned the lands of Pinglu Circuit during the Anshi Rebellion and retreated south to Ziqing Circuit (淄青, headquartered in modern Weifang, Shandong, later renamed Pinglu as a result of this retreat), it was said that Tian Yue, accompanying his mother, moved between different places within Ziqing.
[3] During the campaign, however, as part of Weibo's initial losses, Tian Yue suffered a defeat by several generals attacking Weibo from the south — Li Zhengji the military governor of Pinglu Circuit and Li Zhongchen the military governor of Huaixi Circuit (淮西, headquartered in modern Zhumadian, Henan) — at Chenliu (陳留, in modern Kaifeng, Henan).
Emperor Dezong, instead of receiving them into the palace storage as his father would have, had the silk turned over to the imperial treasury for state use and announced that those were used to satisfy Weibo's and Pinglu's taxes — implicitly informing Tian and Li Zhengji that he was dissatisfied that Weibo and Pinglu were not paying taxes.
As there was an alliance between Weibo, Pinglu, Li Baochen's Chengde Circuit (成德, headquartered in modern Shijiazhuang, Hebei), and Liang Chongyi's Shannan East Circuit (山南東道, headquartered in modern Xiangfan, Hubei) for the military governors to pass their positions to their descendants, Li Baochen had previously supported Tian's succession.
Tian Yue subsequently sent 5,000 soldiers, commanded by his officer Meng You (孟祐), to Chengde to aid Li Weiyue.
He also had another officer, Yang Chaoguang (楊朝光) set up obstacles to try to block any relief forcing coming from Zhaoyi's headquarters at Lu Prefecture (潞州).
In fall 781, with Tian Yue still sieging Linming, the joint forces of three generals loyal to the imperial government — Ma Sui the military governor of Hedong Circuit (河東, headquartered in modern Taiyuan, Shanxi, Li Baozhen the military governor of Zhaoyi, and Li Sheng the commander of the imperial Shence Army (神策軍) — arrived and attacked, first defeating and killing Yang and then defeating Tian at Linming.
Weibo was then in a desperate shape — as within Wei Prefecture there were only several thousand soldiers, and the family members of the dead were all mourning, so the city was filled with wailing and tears.
Tian, in fear and depression, decided to publicly plead his case in order to earn back the people's loyalty.
In tears, he stated:[5] I, Tian Yue, lack talent, but it was with the endorsement of the two older gentlemen of Ziqing [(i.e., Pinglu)] and Chengde that I was able to inherit this post, and thus I did not measure my own strength before I decided to resist the will of the imperial government.
Meanwhile, Li Weiyue was himself suffering heavy defeats at the hands of Zhu Tao the acting military governor of Lulong Circuit (盧龍, headquartered in modern Beijing) and Zhang Xiaozhong — a former Chengde officer who had joined the imperial cause.
However, after yet another major defeat at Zhu's and Zhang's hands, Li Weiyue's officer Wang Wujun turned against him and executed him, submitting to the imperial forces.
He refused to give Chengde's Shen Prefecture (深州, in modern Hengshui, Hebei) to Lulong, as Zhu had requested.
Zhu was angered by Emperor Dezong's refusal to give him any part of Chengde territory (in particular, Shen Prefecture) and requiring him to capture two additional prefectures on his own, while Wang was angered that contrary to Emperor Dezong's implicit promises to give whoever killed Li Weiyue Li Weiyue's offices, he not only received a lesser title, but was in a position where he could easily be destroyed.
Subsequently, when Emperor Dezong ordered armies of Lulong, Yidingcang, and Wang's Hengji Circuit (恆冀, headquartered at Chengde's old capital of Heng Prefecture) to advance south to attack Weibo, Zhu and Wang not only refused but instead advanced south to aid Weibo.
However, when aid from both sides arrived, the overly confident Li Huaiguang ordered an attack with some initial successes, but ultimately suffered a major defeat at Zhu's and Wang's hands.
At the suggestion of Zhu's staff member Li Ziqian (李子千) and Wang's staff member Zheng Ru (鄭濡), they decided to each claim a princely title to show independence from imperial authority, but keep Tang's era name in order not to completely break from Tang.
In fall 783, after a mutiny by the soldiers of Jingyuan Circuit (涇原, headquartered in modern Pingliang, Gansu) at the capital Chang'an forced Emperor Dezong to flee to Fengtian (奉天, in modern Xianyang, Shaanxi), the Jingyuan soldiers supported Zhu Tao's brother Zhu Ci as their leader.
Li Baozhen, however, was able to persuade Wang that such a battle would do him no good regardless of the outcome — that if they were successful, it only benefited Weibo, while it they were not, Hengji would suffer heavy losses.
Meanwhile, Emperor Dezong also sent emissaries to Wang, Tian, and Li Na, persuading them to again submit to Tang authority.
Meanwhile, Emperor Dezong had sent the imperial official Kong Chaofu (孔巢父) to Weibo to meet with Tian Yue, to thank him for his allegiance and to encourage the troops.
He then declared that it was another officer, Liu Zhongxin (劉忠信), who had assassinated Tian Yue, and took over control of the circuit.