The earliest copies of 'The Gallic Wars' that we have are about 800 years older than the original manuscript is alleged to be. How do historians know if this (or other manuscripts whose earliest copy are hundreds of years older than the original) is a genuine depiction of the original work?
I'm confused. Our earliest copies are older than the original manuscript? How would that happen? Surely you mean the autograph (the thing the author wrote) is older than our earliest manuscripts?