Must what the history books say be true?
Not all of them are true. Although history books will be restored as much as possible, they are written by people and subjective. Moreover, the history of China's former dynasties was mostly written by the later dynasties, and there were some rulers' intentions. In fact, even if history is written by witnesses of historical events, there are hundreds of people. The history we are studying now is the history that most historians agree with.