What do we actually know about Joan of Arc?

by jqhoogland

I've been reading The Personal Recollections of Joan of Arc by Mark Twain, and was wondering how accurate it is. If even a fraction is true, she has to rank among the most interesting people who ever lived—a 16 year old peasant girl whose visions of the archangel Michael lead her to become the general of the Armies of France—a story of prophecies come true (of battles won and lost, people killed, wounds sustained), hidden kings uncovered, innate military genius...

The problem is that when I go looking for more information, it's corrupted by the hagiography of Joan. I mean, here's one guy claiming she's the incarnation of Athena and soulmate of the archangel Michael.

How much do we know with certainty? What parts are likely to have been romanticized after her life (or even during her life)? And maybe, on the meta level, how do historians even go about disentangling fact from fiction with such religiously complicated figures?

ttrombonist