Out of this threatening of the Tartars grew a religious persecution, in which Blanche took a part not discreditable to her. When things went wrong in the Middle Ages, it was the fault of the weak and oppressed; if it was not the witches, it was the Jews who had brought misfortune upon the land, and who must be punished before God would be pleased again. In this case it was the Jews, who were accused of lending aid to the Tartars. The popular odium incurred by this accusation encouraged the prosecution of an investigation, ordered by Pope Gregory IX., into the doctrines of the Talmud. France appears to have been the only country where the investigation was actually made. Several Jewish rabbis were haled before the court, presided over by Blanche, to explain and answer for their books. The fairness with which Blanche presided is indeed remarkable when one remembers the severity of the common judicial procedure of the time. The chief rabbi, Yehiel, appealed to her several times against the injustice of being forced to answer certain questions, and she sustained his plea. When Yehiel complained that, whatever the court decided, he and his people could not be protected from the blind rage of the populace, Blanche replied: "Say no more of that. We are resolved to protect you, you and all your goods, and he who dares to persecute you will be held a criminal." When he protested against taking an oath demanded by his persecutors, because it was against his conscience to swear, Blanche decided: "Since it is painful to him, and since he has never taken an oath, do not insist upon it." She reproved the Christian advocates, the learned doctors of the Church, for the unseemly violence of their language, and sought in every way to maintain some sort of impartiality, or at least of decency, in the trial. If she had conducted the trial to the close, there might have been a different sentence from that which condemned the Talmud and ordered it to be committed to the flames. It was through an agent of Blanche, apparently a burgess of Rochelle, that Saint Louis obtained most valuable and timely information in regard to the rebellious preparations of Hugues de Lusignan, Comte de la Marche. This Hugues de Lusignan was the vassal of Alphonse, brother of the king. He had always been inclined to revolt, and this inclination was not lessened by the incitement of his wife, the haughty, high-tempered Isabelle d'Angoulème, widow of King John of England. To have started as Queen of England, on an equal footing with her contemporary, Blanche de Castille, to have seen her miserable husband gradually lose his rich possessions in France, and to find herself now merely a countess and compelled to do homage to a son of her rival,--this must have been the very wormwood of bitterness for Isabelle. The secret agent of Queen Blanche writes a very elaborate account of the conduct of Isabelle and Hugues in 1242.