Textual Research on ZHANG Yue as Prime Minister in Feudal China and Chief Compiling Official for Thirty Years

According to historical document,ZHANG Yue acted as prime minister three times and was in charge of compiling books for thirty years.Acting as prime minister three times does not mean holding the post of chancellor three times but serving as prime minister three times in the period of Kaiyuan,that is,in November of the thirteenth year,in February and August of the seventeenth year of Kaiyuan.He actually held the post of chancellor three times as the document noted,which was from Juanuary to October of the second year of Ruizong Jingyun,September to December of the second year of Xuanzong Xiantian,and from September of the ninth year of Xuanzong to April of the fourteenth year.In charge of compiling books for thirty years should be from the year Jiushi Yuannian whenhe joined in compiling Sanjiaojingzhu as a scholar to the eighteenth year when he died.