The king conducted a serious and searching investigation, to which Mahaut declared herself more than ready to submit, provided that the court were properly constituted and that her cause in the matter of the succession in Artois be in no wise prejudiced. Witnesses on both sides were examined, including the widow of the late King Louis X. and the officers of his household, and on October 9, 1317, a solemn verdict of acquittal resulted for Mahaut. There need be no doubt that the accusations against her had been entirely groundless, merely trumped up in the hope of prejudicing her cause in the eyes of the court. It was only a few months later that Philippe V., after a careful and impartial reexamination of the allegations on both sides, gave judgment in parliament confirming the finding of his father and establishing Mahaut's right to Artois, and ordering that "the said parties (Mahaut and Robert) should desist from all hate and all felonious acts,... and that the said Robert should love the said Countess as his dear aunt, and the said Countess the said Robert as her dear nephew" which both swore to do. While Mahaut was forced to contend in the courts for her authority over Artois, the rebellion of the nobles on the death of Philippe le Bel had not been without serious results in Artois, where she had found it no easy task to maintain any sort of hold upon her vassals. Her chief counsellor, and a faithful servitor he proved, was Thierry d'Hirecon, whom the vassals of Artois hated as a parvenu foreigner he was from the Bourbonnais. In 1314 her vassals began complaining to Mahaut of abuses in the government; but they soon passed from peaceful and legitimate remonstrance to active outrages upon the servants and the property of their countess. In all this Robert d'Artois was no doubt the hidden instigator. One of Mahaut's officers, Cornillot, bailli of Hesdin, who had incurred the enmity of the Sire de Créqui by interfering with his hunting over field and forest without regard for the rights of others, was set upon by a mob of villains who hanged him to a tree; when the weight of his body broke the limb and brought the poor wretch to the ground, they buried him in the earth up to his neck, cut off his head, and carried it as a trophy to the Sire de Créqui. Mahaut despatched her son with a considerable force to arrest two of the rebel vassals in the act of going to war; they were taken to prison, but unwisely released by the intervention of the king, and on the very steps of the prison proclaimed their intention of going over to Mahaut's enemy, Robert. Some of the nobles came upon the young count and his sister, Jeanne, in a country house, insulted them grossly, and even threw mud in the face of the defenceless Jeanne and her brother, who had with them but three knights. Jeanne fled to Hesdin, where Mahaut was at the time, and on the road her carriage was surrounded by a mob of knights, who terrified her by their insults and their threats.