After Tian Xu assassinated Tian Yue and succeeded him in 784 , Emperor Dezong gave Tian Xu his sister Princess Jiacheng in marriage in 785 .
Tian Ji'an was Tian Xu 's third son , and was born of a mother of lowly birth .
After Tian Xu assassinated Tian Yue and succeeded him in 784 , Emperor Dezong gave Tian Xu Tian Xu 's sister Princess Jiacheng in marriage in 785 .
Tian Ji'an was Tian Xu 's third son , and was born of a mother of lowly birth .