Actually, as a historian dnd 5e feat your study of the history can rewards you by giving the below benefits:
- It can increase your intelligence score by 1, to the maximum of 20,
- You can also gain your proficiency in a history skill. Whenever if you already are proficient in the specific skill, You can add double your proficiency bonus to the checks that you do make with it.
- Whenever you take a help action to aid another creature’s ability check, you can even make a DC 15 Intelligence (History) check. Also, on a success, that particular creature’s check can gains the bonus equal to your proficiency bonus, like you share the pertinent advice and also historical examples. But to be received this bonus, then the creature must be able to understand that what you actually are saying.