 After Tian Chengsi died in 779, Tian Yue succeeded him as the military governor of Weibo Circuit with permission from Emperor Daizong, and Tian Xu thereafter served under Tian Yue.Because Tian Yue was thankful to Tian Chengsi for raising him and passing the circuit to him, he treated Tian Xu and his brothers with kindness.He put Tian Xu in charge of the headquarters guards.