Why Was Joan of Arc Burned at the Stake?

On May 28, 1431, Joan of Arc was accused of relapsing into heresy by wearing male clothing again. From the introduction to the article:

"The English claimed many offenses against Joan of Arc. But when they burned her at the stake in Rouen, France on May 30, 1431, they not only immortalized the 19-year-old, but made her a national symbol for the French cause during the long-fought Hundred Years’ War.

Born a peasant in a small French village, the illiterate girl claimed to hear divine voices and see visions of St. Michael, St. Catherine of Alexandria and St. Margaret of Antioch from the age of 13. Their message: Help Charles VII, heir of Charles VI, be named the rightful king of France.

Convincing Charles to let her fight—and dressed as a man—Joan led the liberation of Orleans, triumphed with other victories against the English, and soon Charles VII was crowned. But a series of missteps, including her failure to liberate Paris followed, and on May 23, 1430, she was captured by the Duke of Burgundy’s men, jailed for more than a year and put on trial for charges including heresy, witchcraft and violating divine law for dressing like a man."