When refered to as a "fantasy" Jrr Tolkien is rumored to have flown off the handle and claim that his stories were all real.

He had access to the Vatican's library that not many people had.

There are things like the piks of scottland living in holes and giants of the ancient world which would lend credence.

Edit - a video about ancient little people living in hobit holes https://youtu.be/CtOZBA6eWvA

When refered to as a "fantasy" Jrr Tolkien is rumored to have flown off the handle and claim that his stories were all real.

He had access to the Vatican's library that not many people had.

There are things like the piks of scottland living in holes and giants of the ancient world which would lend credence.