Certain corners of history hold records in great detail, going back long periods of time.
In the world of chess, for example, games several centuries old are documented, move by move, and available for analysis.
Here is a site that claims to have the record of a chess match between the philosophers David Hume and Jean-Jacques Rousseau.
Did such a game ever actually happen? Perhaps, in 1766, in England, before the two philosophers fell out. The ChessGames.com site lists the date of the game as 1765, a date which I think would be impossible.
What sorts of records would we use to corroborate, or debunk? Rousseau’s Dog by David Edmonds and John Eidinow might be a book that answers the question — the two collaborated on an earlier book about chess in history, including Bobby Fischer Goes to War.