Historiography is important for lawmakers to write laws and to change laws so that future does not have to go through same mistakes like that of history.
Step-by-step explanation:
Historiography is the art of studying of how to write history and art of studying the history that has already been written. Law makers are the people who either make new laws or those who change the existing laws.
The need for forming laws or changing the laws is that the people in the future either do not repeat the same mistake as that of history or do not have to go through the troubles of the past.