Trustworthy Historian / Factual History
This refers to historians or history books that record historical facts in an objective and truthful way based on evidences without covering up anything. Objectivity is the ultimate criterion for judging historians or history books in historiography.
However, after reading a huge number of books, Liu Xiang and Yang Xiong came to view Sima Qian as a great historian… His accounts are straightforward and reasonable, accurate and substantive, and free from false praise; they do not cover up evil deeds. (The Han History)
A factual history is one which records both good and evil that have happened. (Su E: Textual Studies by Su E)