The reason why Hanshu started the dynastic history is that Hanshu is the first biographical dynastic history in China, and its records are mainly about the Western Han Dynasty, which lasted for 230 years from the first year of Emperor Gaozu to the fourth year of Emperor Wangmang. The historical materials in Hanshu are very rich and informative, and the times recorded in the book overlap with those recorded in historical books. Both books record the history of the Western Han Dynasty before the middle period of Emperor Wudi.
The use of dynastic history began in Ban Gu, and the so-called "official history" in later generations followed the genre of Hanshu, and later generations said that "Tao cannot be changed". It can be seen that his historical position is very important. At the same time, Hanshu has a prominent position in China's history of China literature. It describes people from all walks of life in the spirit of "remembering", which is plain and vivid and can be said to be a model of biographical literature in later generations.
Ban Gu's adoption of dynastic history is not accidental, but conforms to the requirements of the times. He summarized the historical works of Emperor Wu of the Han Dynasty for about a century and a half from the early years of the Eastern Han Dynasty, and creatively developed them in order to serve the politics of the ruling class at that time. Ban Gu believes that the general historical style of Historical Records puts the Western Han Dynasty at the end of the hundred kings and on the side of Qin Xiang, which is not conducive to promoting "Han De" and it is difficult to highlight the historical position of the Han Dynasty. This is the basis of the use of dating history in Hanshu. Thus, the history of the Han dynasty "includes a generation", starting from the establishment of the Western Han Dynasty and ending with the demise of the new dynasty. In order to highlight Liu Bang, the history of Emperor Gao is put in the first chapter.