李勉
In 776, when Tian Shenyu () the military governor of Biansong Circuit (汴宋, headquartered in modern Kaifeng, Henan) died, the Biansong officer Li Lingyao () seized control of Biansong and wanted to become semi-independent as well. When the imperial government subsequently mobilized the circuits around Biansong to attack Li Lingyao, of all of the nearby circuits, Tian Chengsi not only did not attack Li Lingyao, but also allied with Li Lingyao, sending an army commanded by his nephew Tian Yue to aid Li Lingyao. Tian, however, was defeated by two generals loyal to the imperial government, Li Zhongchen and Ma Sui, and Li Lingyao was himself soon captured by another general loyal to the imperial government, Li Mian, and executed. Tian Chengsi subsequently submitted another apology to Emperor Daizong, and Emperor Daizong, feeling that he had no strength to attack Tian again, pardoned him again and did not require him to visit Chang'an.