Question: What is the date of death of Emperor Yizong Of Tang's father?
Sentence (from "Emperor Xuanzong of Tang (9th century)"): Emperor Xuānzong was the 13th son of Emperor Xianzong (r. 806–820) and an uncle of the previous three emperors, Emperor Jingzong, Emperor Wenzong, and Emperor Wuzong.
Relevant evidence: No