Was Joan of Arc actually a military leader?
Yes in effect, and not in the way the popular image suggests — she held no formal command, is not recorded as having killed anyone, and her contribution was substantially moral and strategic rather than tactical.
The situation. By 1429 the French position in the Hundred Years' War was close to collapse. Orléans was under siege, the Dauphin Charles was uncrowned and of contested legitimacy, and English and Burgundian forces held much of the north.
What she actually did. A teenage peasant from Domrémy, reporting visions instructing her to support Charles, she obtained an audience, was examined by clerics, and was permitted to accompany a relief force to Orléans.
The siege was lifted within days of her arrival. She was present in the fighting, was wounded by an arrow at one assault and returned to the field, and carried a banner rather than fighting — a distinction she herself emphasised at her trial, saying she preferred her banner forty times over to her sword.
Her documented influence: she consistently urged direct attack where commanders favoured caution, and repeatedly proved correct. She was insistent on the coronation at Reims, which was strategically unorthodox and politically decisive — it transformed Charles from a claimant into an anointed king, which mattered enormously in the legitimacy contest.
She had authority without rank, granted informally by the effect she produced on troops and by the Dauphin's support.
The capture and trial. Taken at Compiègne in 1430, sold to the English, and tried by a church court on charges including heresy. The trial was a political proceeding — she was denied counsel, and the decisive charge became wearing male clothing. She was burned at Rouen in 1431, aged about 19.
The transcript survives in unusual detail, and her answers under questioning are frequently cited for their composure — including her response when asked whether she was in God's grace, an unanswerable trap she navigated precisely.
A retrial in 1456 annulled the verdict, and she was canonised in 1920.