Jehanne d’Arc was a very religious French peasant who, (according to her) on request of God was to lead France to certain victories in the 100 years war. She convinced prince Charles the IV to let her lead a portion of the army. Well she lead a siege on Orleans that was successful, followed by more successful battles, and helped Charles become king because of it.
In 1431, she was captured by the enemy and put through a very biased trial where she was declare a witch. She was burned at the stake, age 19. About 20 years later the pope went over the trial, debunked it and declared her innocent, not a witch, and declared her a martyr.
As of 1920 she was canonized as an official saint.
She signed her name Jehanne, not Joan, so that’s how I write it. I studied Jehanne d’Arc in highschool. Sorry if I made any mistakes, I’m on a cell phone and I didn’t go in – depth with my researching this time around.