Though St. Pol had given up the English party, he did not break off his old connection with the Burgundian prince. He fought for him against the insurgent citizens of Ghent, and he even joined in the League of the Public Good, as it was ludicrously styled, and led the vanguard of the count de Charolais, at the battle of Montlhéri. At the peace of Conflans, Louis, in the hope of winning him over from the Burgundian interest, promoted him to be constable of France; and soon after, with the same view, he gave him the hand of Mary of Savoy, the queen’s sister, and granted him a wide extent of territory. These favours did not produce the desired effect. St. Pol seems to have had little gratitude in his nature; and, in this case, he perhaps thought that there was none due for what was rather a bribe than a free gift. As he imagined that his safety consisted in preventing a good understanding between the king and the duke of Burgundy, he was constantly intriguing to keep them at variance, and he alternately betrayed them. His intrigues being discovered, the two princes, during one of their short periods of amity, entered into a compact, by which they declared him their common enemy. The duke of Burgundy promised, that if the constable fell into his hands, he would surrender him to the king within eight days. For this he was to be rewarded by the restoration of St. Quentin, Amiens, and other towns on the Somme. This agreement was of course kept a profound secret. What St. Pol had already done was sufficient to seal his fate; but he roused the anger of Louis still farther, by an act of personal disrespect, and by leaguing with Edward the fourth of England for the invasion of France. It was not, however, till he had got rid of Edward by a treaty, and had artfully contrived to irritate the duke of Burgundy still more against St. Pol, that Louis seriously prepared for taking vengeance on the offender. The negotiation between Edward and Louis had already alarmed the constable, and, to conciliate the latter, he had offered to attack the English. This offer Louis communicated to Edward, who, indignant at the treachery of his recent confederate, sent the letters which he had received from him to the French monarch. Louis was thus furnished with decisive proofs. To the overtures of St. Pol he replied in ambiguous words, the real meaning of which was soon made evident: “I am overwhelmed by so many affairs,” said the Machiavelian monarch, “that I have great need of a good head like yours to get through them.”