在(zai)平定安(an)(an)史(shi)之亂得過(guo)(guo)程中(zhong)，為求得暫時(shi)茍安(an)(an)，唐(tang)代宗措置(zhi)失當(dang)，“瓜分河北地，付授(shou)叛將”，使安(an)(an)史(shi)降將搖(yao)身一變，成(cheng)了(le)(le)由中(zhong)央任命的節度(du)使，保存(cun)了(le)(le)相當(dang)大的離(li)心力。在(zai)平叛過(guo)(guo)程中(zhong)，朝廷還(huan)對內(nei)地掌握(wo)兵權(quan)的刺史(shi)多加(jia)節度(du)使稱號，造成(cheng)了(le)(le)亂后(hou)“方鎮相望于內(nei)地，大者(zhe)連州十余，小者(zhe)猶兼三四”的藩鎮割據的嚴重(zhong)局面。
唐德(de)宗(zong)(zong)即位后，力(li)圖削藩。建中(zhong)二年(nian)(nian)（781）正(zheng)月(yue)(yue)，成德(de)節(jie)(jie)(jie)度(du)使李寶臣(chen)死，子李惟岳向朝(chao)廷請求襲其父位，魏(wei)博(bo)節(jie)(jie)(jie)度(du)使田悅亦(yi)代(dai)為(wei)之(zhi)請。德(de)宗(zong)(zong)堅(jian)決拒絕。李、田遂聯合淄青節(jie)(jie)(jie)度(du)使李正(zheng)己，山南(nan)(nan)東道節(jie)(jie)(jie)度(du)使梁崇義等(deng)起兵(bing)(bing)(bing)反唐。七(qi)月(yue)(yue)李正(zheng)己死，八月(yue)(yue)子李納亦(yi)請襲父位，德(de)宗(zong)(zong)不允，李納遂反。戰事日益(yi)擴大。建中(zhong)四(si)年(nian)(nian)正(zheng)月(yue)(yue)，割據淮西(xi)（今(jin)河(he)南(nan)(nan)汝南(nan)(nan)）的節(jie)(jie)(jie)度(du)使李希烈叛(pan)，攻(gong)襄城（今(jin)屬(shu)河(he)南(nan)(nan)）。德(de)宗(zong)(zong)派哥舒曜討伐，未(wei)果。德(de)宗(zong)(zong)又(you)派涇原(yuan)(yuan)兵(bing)(bing)(bing)去(qu)解圍。時(shi)涇原(yuan)(yuan)節(jie)(jie)(jie)度(du)使朱(zhu)(zhu)泚(ci)(ci)因其弟朱(zhu)(zhu)滔(tao)謀反而被軟禁于(yu)京城。涇原(yuan)(yuan)兵(bing)(bing)(bing)路過長(chang)安(an)時(shi)，因賞賜(si)不周，挾持(chi)節(jie)(jie)(jie)度(du)使姚(yao)令言(yan)嘩變。德(de)宗(zong)(zong)逃往奉(feng)天。叛(pan)軍(jun)(jun)推舉朱(zhu)(zhu)泚(ci)(ci)為(wei)首領，史稱(cheng)(cheng)(cheng)涇原(yuan)(yuan)之(zhi)變。朱(zhu)(zhu)泚(ci)(ci)率軍(jun)(jun)攻(gong)奉(feng)天，未(wei)下。此時(shi)朝(chao)廷援兵(bing)(bing)(bing)已逼長(chang)安(an)，朱(zhu)(zhu)泚(ci)(ci)退守長(chang)安(an)。不久唐將(jiang)領李懷(huai)光(guang)與朱(zhu)(zhu)泚(ci)(ci)聯合。德(de)宗(zong)(zong)被迫又(you)奔梁州(zhou)（今(jin)陜西(xi)漢中(zhong)）。興元元年(nian)(nian)（784）五月(yue)(yue)，唐將(jiang)領李晟等(deng)攻(gong)克長(chang)安(an)，德(de)宗(zong)(zong)于(yu)七(qi)月(yue)(yue)返回(hui)。朱(zhu)(zhu)泚(ci)(ci)被部下所(suo)殺。朱(zhu)(zhu)滔(tao)病(bing)死。李懷(huai)光(guang)兵(bing)(bing)(bing)敗自縊。因在(zai)這次戰爭中(zhong)，有四(si)人稱(cheng)(cheng)(cheng)王(wang)(wang)(wang)(wang)，兩人稱(cheng)(cheng)(cheng)帝(di)(di)，即朱(zhu)(zhu)滔(tao)稱(cheng)(cheng)(cheng)冀王(wang)(wang)(wang)(wang)，王(wang)(wang)(wang)(wang)武(wu)俊稱(cheng)(cheng)(cheng)趙王(wang)(wang)(wang)(wang)，田悅稱(cheng)(cheng)(cheng)魏(wei)王(wang)(wang)(wang)(wang)，李納稱(cheng)(cheng)(cheng)齊王(wang)(wang)(wang)(wang)，朱(zhu)(zhu)泚(ci)(ci)稱(cheng)(cheng)(cheng)秦(qin)帝(di)(di)，李希烈稱(cheng)(cheng)(cheng)楚帝(di)(di)，故又(you)稱(cheng)(cheng)(cheng)二帝(di)(di)四(si)王(wang)(wang)(wang)(wang)之(zhi)亂。
