唐德宗建中四年淮西李希烈叛,四月德宗以哥舒曜将禁军万余人出讨,哥舒曜收复汝州,后被李希烈将兵三万困于襄城。九月德宗命河南都统、宣武节度使李勉与神策将刘德信等将兵解襄城之围。刘德信等援军于汝州郏城县(今河南郏县)扈涧为李希烈将李克诚伏击,官军大败,遗弃辎重甚众,是为扈涧之败。扈涧之败是历史上唐军在淮西战场上一次重大失利,因扈涧之败,襄城更为危急,德宗急调泾原五千士卒驰援襄城,结果路经长安时士卒倒戈哗变,德宗仓皇出奔奉天。可以 Tang Dezong built four years in Huai Xi Li Xirei rebel, April Dezong to Ge Shu Yao will ban the army more than a thousand people out of discussion, Costa Rica recovered Yu Zhou, Li Xi Lie generals will be trapped in Xiangcheng thirty thousand. Deutism in September in Henan Province are all unified, Xuanwu Jiedushi Li Mian and the generals Liu Dexin and other soldiers will Bingxiang Xiangcheng Wai. Liu Dexin and other reinforcements in Ruzhou Tancheng County (now Henan Lixian) Hu Jian Li Xi Lie Li Kecheng Ambush, the defeat of the military, abandoned much emphasis on the public, is the defeat Hujian. Hu Jian defeat is the history of the Tang army in the battlefield of Huaiyin a major defeat, because the Hujian defeat, Xiangcheng more critical, Germany Zong Jing Jingyuan five thousand soldiers to aid Xiangcheng, the result of Chang’an Shi Shizhu down mutiny Dezong barracks run to heaven. can