Old Book of Tang: Crown Prince Li Heng ascended the throne at Lingwu; the ministers, citing that the retired emperor had transferred the throne…
Crown Prince Li Heng ascended the throne at Lingwu; the ministers, citing that the retired emperor had transferred the throne, prayed for his long life.
禮畢，冕等跪進曰：「自逆賊恁陵，兩京失守，聖皇傳位陛下，再安區宇，臣稽首上千萬歲壽。
Location: 舊唐書 卷10 至德1年
Crown Prince Heng was enthroned at Lingwu as Emperor Suzong; Xuanzong was honored as Shanghuang Tiandi and the era changed to Zhide.
甲子，即皇帝位于靈武，尊皇帝曰上皇天帝，大赦，改元至德
Location: 新唐書 卷006 肅宗·代宗 至德1年7月