Tian Chengsi
Tian Xing was born in 764, during the reign of Emperor Daizong. He was the second son of Tian Tingjie (), a cousin of Tian Chengsi, who was then ruling Weibo Circuit as its military governor, in "de facto" independence from the imperial government. It was said that in Tian Xing's youth, he studied the Confucian classics but particularly military strategies. He was also said to be capable in horsemanship and archery, and was brave and polite. Tian Chengsi favored him and had him named Xing (meaning "prosperity"). After Tian Tingjie died in 782 in distress (after being unable to dissuade Tian Chengsi's nephew and successor Tian Yue from turning against the imperial government), Tian Xing's older brother Tian Rong () became in charge of watching over his younger brothers. On one occasion, after Tian Xing won an archery contest among Weibo soldiers, Tian Rong battered him and told him, "If you do not keep your abilities hidden, disaster will come to you." Traditional historians credited Tian Rong's teaching for Tian Xing's ability to survive in the following years.