在平(ping)定安(an)史(shi)之亂(luan)得(de)過(guo)程中(zhong),為求(qiu)得(de)暫(zan)時茍安(an),唐代宗措置失(shi)當(dang),“瓜分河北地,付(fu)授叛將(jiang)”,使安(an)史(shi)降將(jiang)搖身一(yi)變,成(cheng)了由中(zhong)央(yang)任命的(de)(de)節(jie)度使,保存了相當(dang)大的(de)(de)離心力。在平(ping)叛過(guo)程中(zhong),朝廷(ting)還(huan)對內地掌(zhang)握兵權的(de)(de)刺史(shi)多加節(jie)度使稱號(hao),造成(cheng)了亂(luan)后(hou)“方鎮相望于內地,大者(zhe)連州十余,小者(zhe)猶兼三四”的(de)(de)藩鎮割(ge)據的(de)(de)嚴重局面。
唐(tang)(tang)德(de)(de)宗(zong)即位后,力圖(tu)削藩。建中(zhong)(zhong)(zhong)二年(nian)(781)正月(yue),成德(de)(de)節(jie)度(du)(du)使(shi)(shi)李(li)(li)(li)(li)寶(bao)臣死(si)(si),子(zi)李(li)(li)(li)(li)惟岳(yue)向朝廷(ting)請(qing)求襲其(qi)父位,魏博節(jie)度(du)(du)使(shi)(shi)田(tian)悅亦代為之請(qing)。德(de)(de)宗(zong)堅決拒(ju)絕。李(li)(li)(li)(li)、田(tian)遂(sui)聯(lian)合淄青(qing)節(jie)度(du)(du)使(shi)(shi)李(li)(li)(li)(li)正己,山南東道節(jie)度(du)(du)使(shi)(shi)梁(liang)崇(chong)義(yi)等起兵(bing)(bing)反(fan)唐(tang)(tang)。七月(yue)李(li)(li)(li)(li)正己死(si)(si),八月(yue)子(zi)李(li)(li)(li)(li)納(na)亦請(qing)襲父位,德(de)(de)宗(zong)不允,李(li)(li)(li)(li)納(na)遂(sui)反(fan)。戰事日益擴大。建中(zhong)(zhong)(zhong)四年(nian)正月(yue),割據淮西(今河(he)(he)南汝南)的節(jie)度(du)(du)使(shi)(shi)李(li)(li)(li)(li)希(xi)烈叛(pan),攻(gong)(gong)襄城(cheng)(今屬河(he)(he)南)。德(de)(de)宗(zong)派(pai)哥舒曜討伐,未(wei)果。德(de)(de)宗(zong)又(you)派(pai)涇原(yuan)兵(bing)(bing)去(qu)解圍(wei)。時涇原(yuan)節(jie)度(du)(du)使(shi)(shi)朱(zhu)(zhu)(zhu)泚(ci)(ci)因其(qi)弟朱(zhu)(zhu)(zhu)滔謀反(fan)而(er)被軟禁(jin)于京城(cheng)。涇原(yuan)兵(bing)(bing)路過長(chang)安(an)時,因賞賜不周,挾持(chi)節(jie)度(du)(du)使(shi)(shi)姚令言嘩(hua)變。德(de)(de)宗(zong)逃往(wang)奉(feng)天(tian)。叛(pan)軍(jun)推舉(ju)朱(zhu)(zhu)(zhu)泚(ci)(ci)為首領,史稱(cheng)涇原(yuan)之變。朱(zhu)(zhu)(zhu)泚(ci)(ci)率軍(jun)攻(gong)(gong)奉(feng)天(tian),未(wei)下。此時朝廷(ting)援兵(bing)(bing)已逼長(chang)安(an),朱(zhu)(zhu)(zhu)泚(ci)(ci)退守長(chang)安(an)。不久唐(tang)(tang)將領李(li)(li)(li)(li)懷(huai)光與朱(zhu)(zhu)(zhu)泚(ci)(ci)聯(lian)合。德(de)(de)宗(zong)被迫(po)又(you)奔梁(liang)州(今陜西漢(han)中(zhong)(zhong)(zhong))。興元元年(nian)(784)五月(yue),唐(tang)(tang)將領李(li)(li)(li)(li)晟等攻(gong)(gong)克長(chang)安(an),德(de)(de)宗(zong)于七月(yue)返回。朱(zhu)(zhu)(zhu)泚(ci)(ci)被部(bu)下所殺。朱(zhu)(zhu)(zhu)滔病死(si)(si)。李(li)(li)(li)(li)懷(huai)光兵(bing)(bing)敗自縊(yi)。因在這次戰爭(zheng)中(zhong)(zhong)(zhong),有四人稱(cheng)王(wang)(wang),兩人稱(cheng)帝(di),即朱(zhu)(zhu)(zhu)滔稱(cheng)冀王(wang)(wang),王(wang)(wang)武俊(jun)稱(cheng)趙王(wang)(wang),田(tian)悅稱(cheng)魏王(wang)(wang),李(li)(li)(li)(li)納(na)稱(cheng)齊王(wang)(wang),朱(zhu)(zhu)(zhu)泚(ci)(ci)稱(cheng)秦帝(di),李(li)(li)(li)(li)希(xi)烈稱(cheng)楚帝(di),故又(you)稱(cheng)二帝(di)四王(wang)(wang)之亂。