I am looking for a genre that I cannot really find to have a common name, but what can be described as a secret or hidden history of the world.
Much like Lovecraft where his heroes were studying ancient manuscripts to uncover the ancient and forgotten knowledge. Where the ancient people knew things that were discovered long after that can only be explained by some facts unknown to modern science.
I tried to google, but could not find anything interesting. Since it's not really allowed to ask about the authors themselves I would appreciate any hints that can help me google this. A common name for the genre, or some other least common denominator that I can use to search e.g.
P.S. Not looking for "documentary" conspiracy theories, but pure fiction.