People who dedicate their careers to studying certain periods of history (medieval European, Renaissance, etc), why?

I'm sorry in advance if this isn't the right sub, but I randomly thought of this question and I didn't know where else to post. But basically I'd like to know what one would expect on dedicating one's life to becoming an expert on a tiny point in our history. What is there to learn or understand that hasn't been already discovered by historians in the past? What do you look for when you "study" those periods of history? Besides being a professor or teacher, what careers can one do with a masters in say medieval history?

Submitted October 28, 2019 at 07:29PM by I_love_limey_butts https://ift.tt/2Ww686d