在平定(ding)安史之亂得(de)(de)過(guo)程中(zhong),為求得(de)(de)暫時茍(gou)安,唐(tang)代宗措置失(shi)當,“瓜分河(he)北(bei)地,付授叛將(jiang)”,使安史降(jiang)將(jiang)搖身一變,成了(le)由(you)中(zhong)央任命的節度使,保存了(le)相當大的離(li)心(xin)力(li)。在平叛過(guo)程中(zhong),朝廷(ting)還對內(nei)地掌握(wo)兵權的刺史多加節度使稱號,造成了(le)亂后“方鎮相望于內(nei)地,大者(zhe)連州十余,小者(zhe)猶兼三(san)四(si)”的藩鎮割據的嚴重局(ju)面。
唐(tang)德(de)宗(zong)即(ji)位(wei)后,力(li)圖削藩。建(jian)中(zhong)二年(nian)(nian)(781)正(zheng)月(yue)(yue)(yue),成德(de)節(jie)度(du)(du)(du)(du)(du)使(shi)(shi)(shi)李(li)(li)(li)(li)寶臣(chen)死(si),子李(li)(li)(li)(li)惟岳向朝廷(ting)請求襲其父(fu)位(wei),魏博節(jie)度(du)(du)(du)(du)(du)使(shi)(shi)(shi)田(tian)悅亦代為(wei)之請。德(de)宗(zong)堅(jian)決拒絕。李(li)(li)(li)(li)、田(tian)遂(sui)聯合淄青節(jie)度(du)(du)(du)(du)(du)使(shi)(shi)(shi)李(li)(li)(li)(li)正(zheng)己,山南(nan)(nan)東道節(jie)度(du)(du)(du)(du)(du)使(shi)(shi)(shi)梁(liang)崇義等起兵反(fan)唐(tang)。七月(yue)(yue)(yue)李(li)(li)(li)(li)正(zheng)己死(si),八月(yue)(yue)(yue)子李(li)(li)(li)(li)納亦請襲父(fu)位(wei),德(de)宗(zong)不(bu)(bu)允,李(li)(li)(li)(li)納遂(sui)反(fan)。戰(zhan)事日益(yi)擴大(da)。建(jian)中(zhong)四年(nian)(nian)正(zheng)月(yue)(yue)(yue),割據淮西(今河南(nan)(nan)汝(ru)南(nan)(nan))的節(jie)度(du)(du)(du)(du)(du)使(shi)(shi)(shi)李(li)(li)(li)(li)希(xi)烈叛,攻(gong)(gong)襄(xiang)城(cheng)(今屬(shu)河南(nan)(nan))。德(de)宗(zong)派哥舒(shu)曜討伐,未果(guo)。德(de)宗(zong)又(you)(you)派涇(jing)原(yuan)(yuan)兵去解(jie)圍。時涇(jing)原(yuan)(yuan)節(jie)度(du)(du)(du)(du)(du)使(shi)(shi)(shi)朱(zhu)(zhu)泚(ci)(ci)(ci)因其弟(di)朱(zhu)(zhu)滔謀反(fan)而(er)被軟禁于(yu)京城(cheng)。涇(jing)原(yuan)(yuan)兵路過(guo)長(chang)(chang)安(an)時,因賞(shang)賜(si)不(bu)(bu)周,挾持(chi)節(jie)度(du)(du)(du)(du)(du)使(shi)(shi)(shi)姚(yao)令言嘩變(bian)。德(de)宗(zong)逃往(wang)奉天。叛軍(jun)推(tui)舉朱(zhu)(zhu)泚(ci)(ci)(ci)為(wei)首領,史稱(cheng)(cheng)涇(jing)原(yuan)(yuan)之變(bian)。朱(zhu)(zhu)泚(ci)(ci)(ci)率軍(jun)攻(gong)(gong)奉天,未下。此時朝廷(ting)援兵已逼長(chang)(chang)安(an),朱(zhu)(zhu)泚(ci)(ci)(ci)退守長(chang)(chang)安(an)。不(bu)(bu)久唐(tang)將(jiang)(jiang)領李(li)(li)(li)(li)懷(huai)光與朱(zhu)(zhu)泚(ci)(ci)(ci)聯合。德(de)宗(zong)被迫(po)又(you)(you)奔梁(liang)州(zhou)(今陜西漢中(zhong))。興元(yuan)元(yuan)年(nian)(nian)(784)五月(yue)(yue)(yue),唐(tang)將(jiang)(jiang)領李(li)(li)(li)(li)晟等攻(gong)(gong)克(ke)長(chang)(chang)安(an),德(de)宗(zong)于(yu)七月(yue)(yue)(yue)返回。朱(zhu)(zhu)泚(ci)(ci)(ci)被部下所(suo)殺(sha)。朱(zhu)(zhu)滔病死(si)。李(li)(li)(li)(li)懷(huai)光兵敗自縊。因在這(zhe)次(ci)戰(zhan)爭中(zhong),有(you)四人稱(cheng)(cheng)王(wang),兩人稱(cheng)(cheng)帝(di)(di),即(ji)朱(zhu)(zhu)滔稱(cheng)(cheng)冀王(wang),王(wang)武俊(jun)稱(cheng)(cheng)趙(zhao)王(wang),田(tian)悅稱(cheng)(cheng)魏王(wang),李(li)(li)(li)(li)納稱(cheng)(cheng)齊王(wang),朱(zhu)(zhu)泚(ci)(ci)(ci)稱(cheng)(cheng)秦帝(di)(di),李(li)(li)(li)(li)希(xi)烈稱(cheng)(cheng)楚帝(di)(di),故(gu)又(you)(you)稱(cheng)(cheng)二帝(di)(di)四王(wang)之亂。