Joan Vol 1

From the ComicsOne edition

Set in Medieval France during the Hundred Years War, Joan is the story of Emil, a young woman raised as a man by Baudricourt, the same person who took Joan of Arc under his wing. Guided by visions of La Pucelle (the name given to Joan by followers), Emil seeks to unite France under the divine rule of the King. In her quest, Emil goes to the same places Joan had traveled through, and gains her own followers in the process. However, Emil is opposed by the dauphin Louis, a brute enforcer who fears no divine power and wishes to make his own bid to rule the country.

Source: Anime News Network Encyclopedia