唐德宗李适生於天寶盛世,青少年成長時期曾經歷安史之亂、藩鎮割據、權閹弄權、吐蕃入寇、出使迴紇,國家由盛轉衰,兵荒馬亂,民不聊生的景象均曾目睹或耳聞。德宗盛年登極,改革惡習,令人耳目一新,然皆細節,有益於個人廉潔清新形象之確立,無助於解決內政外交之困境。接二連三昧於事實的政策,激起河北藩鎮連兵、涇原兵變,乘輿一幸奉天,李懷光叛變,再幸梁州。原因之一,固可說是「姦臣」誤國,推其原委,德宗實難辭其咎。德宗猜忌文武大臣,不使久安其位,尤忌結黨,任一勢力坐大,立即拔擢另一勢力與之對抗,並整肅之,所謂「姦臣」係德宗遂行權力恐怖平衡治術之棋子。
Born at Tien-Bou Area, De-Tzung, emperor of the Tang Dynasty, experienced An-Shi Rebellion, Barbarians' violence, Enunch's lust for power, Tibets' attacks, and diplomatic mission to Uigurs. Due to these restlessness, the empire had shifted from powerful strength to weakness, which led to people’s depression and poverty. Thereby, when succeeding to the leadership, De-Tzung determined to get rid of all drawbacks related, which were expected to make possible new, clean and honest impression. Nevertheless, these renovations resolved no diplomatic troubles at all; to the contrary, wrong policies resulted in united forces of Barbarians in Ho-bei (河北), military rebellion at Chin-Yuan (涇原), uprising revolt of Li Hui-Kuang (李懷光) who defeated Lian-state (梁州) furthermore. All these defeats arose from ”evil officials”, for whom De-Tzung should be blamed. De-Tzung avoided union of certain parties; thereby, no officials would hold any post for long, which would be counterpart of other renewed parties/posts anytime anyplace. These ”evil officials' were actually De-Tzung's tools to make possible ”power balance”.