There was a lot of backbiting between the two mistresses of the two courts toward the end of Francis's reign. Anne had a group of poets and satirists who said and wrote nasty things about Dianne's age. She replied by having herself painted and sculpted in the nude that simultaneously dropped their jaws and shut them up. The duel came out of the teasing of Jarnac by either Henri or Dianne  on his ability support himself financially at court due to his limited means. Jarnac replied that he was taken care of by his stepmother (who was a very wealthy woman). After it had passed through the rumor mill, it came out that Jarnac was sleeping with his stepmother. The story passed to his father, Charles Chabot. Jarnac heard the altered story and blew up. He said that the story was a lie and that anyone who said it was a liar. Then he dashed back to his parents to explain the whole thing. His father announced that if Jarnac had not issued the challenge, he would. This left Henri's circle with a problem. They could ignore the challenge, for it would mean that Dianne or he were liars and that would score too many points for Anne. Dianne obviously could not answer the challenge except through the courts. Since the legal system was as fully developed as our own, that could take years. The Dauphin could not, as he was forbidden by law to duel. It looked as though Jarnac and Anne had checked Dianne and Henri. When by position or infirmity someone could not accept a challenge it was customary for them to select a champion to represent them. So it is not surprising that Chataigneraie, the best fighting man in France, and the Prince's circle, stepped forward as the champion. He stated that Jarnac had said the damning words to him. That changed the whole dynamic because at that moment Jarnac was a dead man. Looked as though Dianne and Henri had moved out of check and were in a position to checkmate Jarnac and Anne. But Francis was a wily old fox and forbade the duel , so the case went to Court for defamation of the character of Madame de Jarnac and the matter was closed. Signor Piero Strozzi, an Italian friend of Chataigneraie, suggested that he simply meet Jarnac somewhere and murder him and skip to Venice until the whole thing blew over. The friend would even send money to Venetian bankers to tide him over. Chataigneraie refused the offer. There is an entirely different view given by Charles Mackay who writes, Chataigneraie, and Jarnac, had been friends from their early youth, and were noted at the court of Francis I for the gallantry of their bearing and the magnificence of their retinue. Chataigneraie, who knew that his friend's means were not very ample, asked him one day, how it was that he contrived to be so well provided? Jarnac replied, that his father had married a young and beautiful woman, who, loving the son better than the sire, supplied him with as much money as he desired. La Chataigneraie told the Dauphin, the Dauphin to the King, the King the courtiers, the courtiers to all their acquaintances. In a short time it reached the ears of the old Lord de Jarnac, who sent for his son, and demanded to know how the report originated, and whether he had done it or said it. De Jarnac denied he had said so, or given reason to the world to say so. He asked his father to accompany him to court, and confront their accuser. They went, and the younger De Jarnac, entering a room where the Dauphin, La Chataigneraie, and several courtiers were present, said, 'That whoever had asserted, that he maintained a criminal connection with his mother-in-law, was a liar and a coward!' Chataigneraie stood forward, and stated, that Jarnac himself said so, and he would force him to confess it. This could not be met or rebutted by any legal proof, and the royal council ordered that it should be decided by single combat. This can be given as Chataigneraie or the Dauphin's side of the story and gives an entirely different complexion to the affair. We can no more settle this than the royal council could.