I just received what seems to be authentic letters between Napoleon Bonaparte and his wife Joséphine. The letters were written while Napoleon was in exile.
They were handed down to me by a family member who received them years ago. We obtained them in the late 1800's. The paper seems to be the exact paper from that time. You can visibly see the ink marks on the paper with a magnifying glass.
I don't want to take any pictures just yet because if they do turn out to be real, I don't want to show them until after they have been reviewed. I've been told if they are real, they are priceless.
Whats the best way to authenticate them 100%?
A couple of details: Napoleon divorced Josephine in 1810 and married the Austrian Princess Marie Louise four years before his first abdication. He first went into exile in 1814,then after his return and defeat at Waterloo, was sent into exile again in 1815. Josephine died a month or so before Napoleon's first abdication and exile in 1814, so if they make no reference to Josephine being dead, or there are ones ostensibly from Josephine then it's likely they're fake, unless by 'exile' you mean they were written when he was on campaign in Egypt in 1798, in which case they might be genuine - but they will probably be signed and styled differently than they would be after he became Emperor.
Further, Napoleon had notoriously terrible handwriting. Here's a sample, albeit one from 1796 rather than the 1810s. Thus if the handwriting is decent, it's probably not in Napoleon's own hand. That doesn't mean they aren't real, but it does mean you need to tread carefully.
The best thing would probably be to take careful photographs and contact the Archives Nationale in France - but be prepared to be told that they are fake.
