The modern historian concerned with the earlier periods of Chinese history remains heavily dependent on the material contained in the standard dynastic histories. It is therefore essential for him to subject the texts of these works to the most rigorous critical scrutiny, for they are rarely the simple product of a single author or group of compilers that they appear to be at first sight. A first step in such a critical scrutiny must be an understanding, in the greatest possible detail, of the process by which the “normative” official historical record of a period came into being, in order to assess the ways in which the process of compilation influenced the final record. Failure to understand such technical matters can blunt our critical interpretation of the histories almost as much as failure to appreciate and make allowance for the conventional intellectual attitudes of official “Confucian” historiography or to understand which specific issues and political problems seemed of paramount importance to contemporary official historians.

This study provides such critical scrutiny of history writing in the T'ang period, and shows how changes in the historiographical process gave rise to marked variations both in the reliability and in the level of detail of the record for different reigns that are reflected in the surviving histories.

Critical investigation of T'ang historical sources is not, of course, anything new.