Let me start off by saying that I often support science and believe in widely accepted theories such as the big bang and the holocaust and what have you. Secondly, I'm not big on conspiracy theories although I do find it interesting to read and talk about them.
That being said; how do we ACTUALLY know any of our historical facts or indeed facts? For example: When I speak to Christian historians they explain how certain documents verified that Jesus lived, but I wouldn't be surprised that Lord Voldemort would be perceived the next Hitler in 3020 because they found many HP books in different places. And I can imagine that people can fabricate documents in multiple regions if there was a cult like following was happening. To me, it doesn't prove anything.
Now, when I see Martin Luther King speeching on video and related protests of those times on video, that's enough for me to verify it happened. But if you tell me that Genghis Khan swooped in and dominated almost half of the world, how do you really know?
The main reason I don't tend to accept that 'found documents' prove something its existence is that the Victor of any war determines the outcome. I would argue that every piece of history we know is either false or adapted. Who knows how many cultures and religions have been obliterated from this world by their enemies who then changed the whole logbook.
Sorry for the rambling. I'm just curious when you Historians actually determine History is valid or accurate?
There's always more that can be said, but you might like this older thread from /u/Superplaner, /u/Instantcoffees and others;