Joan of Arc was instrumental in which Hundred Years' War battle?

Joan of Arc (1412-1431) was present at the Siege of Orleans (1428-1429) during the Hundred Years' War. The war was fought between the ruling houses of England and France for the control of France from 1337 to 1453. England had the upper hand with such devastating victories as Crecy (1346), Poitiers (1358), and Agincourt (1415).

From this devastation, Joan of Arc emerged. She was a simple peasant girl who claimed she had visions from saints who told to her to support King Charles VII and reclaim France from the English. Gaining an audience with Charles, he allowed her to join the fight at Orleans. Orleans was strategically important,; its fall would allow for the conquest of the rest of France.

Incredibly her advice was accepted as she was thought to have been divinely inspired. Her mere presence was a morale booster. The Siege of Orleans was raised nine days after she arrived. She also pushed for further military advances to ensure coronation of Charles at Rheims, which would be a significant symbolic sign of French power. The Siege of Orleans proved to be a turning point in the war as French successes continued until final victory in 1453.

Tragically, Joan wasn't to see the final victory. Captured by the Burgundians, allies of the English, she was found guilty of heresy and crossdressing. She was burned at the stake on May 30, 1431.