Jeanne had claimed she was shown vision of Saints Mic hall and Catherine that motivated her to do whatever necessary to make sure the Dauphn Charles was crowned King of France. The previous few days' worth of blog posts show that she did, in fact, help achieve this goal. Unfortunately, she reached a point where her desire for military action was no longer consistent with the new King Charles' Armagnac party's desire for less-bloody negotiation with the Burgundians.
The trial was headed by Bishop Pierre Cauchon. Although French, Cauchon was allied to the Burgundian party (he was the ambassador to the Duke of Burgundy), and had Anglo-centric leanings. If Joan could be proven not to be an agent of God, then they could delegitimize Charles VII and place the use of Burgundy on the throne.
Three notaries were appointed to each make an account of the trial while it proceeded in February 1431. Translated from Middle French to Latin in 1435, they were preserved sufficiently that there are three copies extant. An investigation in the 1450s spoke to many of the 115 witnesses that were Brough forth in the trial and uncovered much new information that had not been recorded during the trial.
Cauchon arranged for investigators to look into Jeanne's character. The Duchess of Bedford oversaw an examination into the maid's claims of virginity, and declared them true. An investigator sent to her home town of Domrémy came back with the statement that he could hear nothing about her character "that he would not have liked to find about his own sister." (Cauchon declared that investigator a bad man and refused to pay his salary.)
A trial for heresy required some specific facets according to canon law: the presence of the vice-inquisitor, permission for Cauchon to preside over (he was outside his diocese of Beauvais), and equal numbers of prelates representing both sides of the debate. Joan said she would attend, but wanted to hear Mass. She was not allowed to hear Mass, and was not allowed to attend the trial because she refused to wear anything but a (male) soldier's garments. Complaints about her improper clothing were raised again and again. (The illustration is by a 19th century artist, depicting the Cardinal of Winchester interrogating her in her prison cell.)
She refused to reveal any details of what her visions said to her, claiming that she shared them only with Charles and would not share them with anyone else. She would repeatedly say "Everything I have done is at God's command."
Weeks of questioning were to determine her standing with God and the Church and to create the list of potential charges. Tomorrow I'll explain the actual trial that followed, the compromise about clothing she offered them, and her execution.