唐朝自安史之亂後，以宰相為首的官僚體系，面臨諸多嚴峻挑戰。德宗時期的宰相群，因黨爭互相攻訐，致使引發地方反彈，造成奉天之難並導致河北、淮西等地藩鎮自立，憑藉地方勢力，阻斷中央與地方官員遷轉。憲宗繼承前朝的宰相群黨爭與藩鎮自立兩大問題。為求重振朝廷威望，解決地方勢力，宰相選任成為朝政治理首要之務。憲宗為解決新興的地方藩鎮勢力，重用世族子弟為宰相，以夾帶郡望的舊勢力，力圖削緩地方軍武的新勢力。是中唐時期，世族政治再次崛起。

Since the An-shi Rebellion of the Tang Dynasty, the bureaucracy led by the chancellor faced many serious challenges. During the reign of Emperor Dezong, the conflicts between the different cliques led to local backlash and caused Jingyuan Mutiny. As a result, Fanzhen in Hebei and Huaixi and blocked the relocation between central and local officials by their local force. Xianzong inherited the two major problems from the previous emperor, namely, the party disputes among the chancellors and the separatist regions of Fanzhen. In order to revive the prestige of the imperial court and solve the problem of expanding separatist forces, the task is to appoint proper officials in the bureaucratic system. In order to solve the emerging local clan power, Xianzong reappointed the sons of the clans as prime ministers, in order to interfere with the old power of county prestige and try to slow down the new power of local military and military. It was during the Middle Tang Dynasty that clan politics rose again.