Jean was a magician, votary of Apollonius of Tyana. He travelled from one town to another wearing a collar of iron and made his living by performing deeds of charletanry. He achieved some fame in Lyon for his cures, and he was even allowed to meet the sovereign. He presented him with a dazzling enchanted sword, and it became surrounded by nine drawn knives during battle. He also gave the prince a magic shield which contained a mirror, and the mirror could tell the greatest secrets.