Joan of Arc was burned in Rouen in 1431 as a relapsed heretic

Joan of Arc was burned at the stake in the Old Market Square of Rouen on the morning of 30 May 1431, aged about 19, after a church court declared her a relapsed heretic — not, as is often said, a witch. The University of Paris had wanted her tried for sorcery, but the verdict that killed her rested on heresy.

The relapse was the trap. A year after she was captured outside Compiègne, and after months of questioning by judges led by Bishop Pierre Cauchon, an exhausted Joan signed an abjuration in the cemetery of Saint-Ouen on 24 May and agreed to give up men’s clothing. Sentenced to life imprisonment, she was put back in a cell guarded by English soldiers; by 27 May she had retracted. On 29 May the court declared her relapsed and handed her over to the English.

After the burning, the English had her ashes thrown into the Seine so nothing could become a relic. A retrial authorised by Pope Calixtus III heard 115 witnesses and declared the condemnation null and void on 7 July 1456; she was canonised in 1920.

The relics that turned out to be a mummy

In 1867 a jar labelled “Remains found under the stake of Joan of Arc, virgin of Orleans” turned up in the attic of a Paris pharmacy. Inside were a charred-looking human rib, lumps of what seemed to be burnt wood, a 15-centimetre scrap of linen and a cat’s thigh bone.

In results reported in 2007, forensic scientist Philippe Charlier and his team put them to the test. Carbon-14 dating placed the material between the third and sixth centuries BC, the linen bore a coating typical of mummy wrappings, and the samples matched Egyptian mummies, which Europeans had long used in medicinal remedies. The jar had surfaced just as historians were turning a long-forgotten Joan into a national myth.