신당서
Despite Guo's high status, little is firmly established about his background or career except for the years that he served as chancellor—as, unusual for a chancellor, he did not have a biography in either the "Old Book of Tang" or the "New Book of Tang". He was from Yingchuan (潁川, in modern Xuchang, Henan.) According to the table of chancellors in the "New Book of Tang", his father was Guo Chufan (郭處範), who at one point served as the secretary general of Zhucheng County (諸城, in modern Weifang, Shandong).