Shortly after, the king of Poland, who was a determined enemy to the grand master of Prussia, (and who had but faintly accepted of Christianity in order to obtain his kingdom) marched his Polanders to the assistance of the infidels, whom he strongly pressed to renew the war against Prussia, insomuch that, eight days after this defeat, the king of Poland, in conjunction with the aforesaid two kings, assembled an army of six hundred thousand men, and marched against the grand master of Prussia, and other Christian lords. A battle ensued, which was lost by the Christians, who had more than sixty thousand killed and wounded. In the number of dead were the grand master of Prussia, with a noble knight from Normandy, called sir John de Ferriere, son to the lord de Ferriere, and another from Picardy, son to the lord du Bos d’Ancquin. It was currently reported that the day had been lost through the fault of the constable of Hungary, who commanded the second squadron of the Christians, by running away with all his Hungarians. The infidels, however, did not gain the glory without loss,--for without counting the Polanders, who had ten thousand men slain, they lost upward of six-score thousand men, according to the reports of the heralds, and the bastard of Scotland, called the count de Hembe[60]. The lord de Kyeuraing and John de Grez, Hainaulters, were there, and with them full twenty-four gentlemen, their countrymen, who were unhurt at this battle, and returned home as speedily as they could. After the engagement, the infidels entered Prussia, and despoiled many parts of it, and took twelve inclosed towns in a short time and destroyed them. They would have persevered in their wickedness, and have done further mischief, had not a valiant knight of the Teutonic order, named Charles de Mouroufle[61], rallied a great number of the Christians who had fled, and by his prudence and vigour regained the greater part of these towns, and finally driven the infidels out of the country[62]. CHAP. XX. THE DUKE OF BERRY QUITS PARIS, AND RETIRES TO HIS OWN ESTATES.--HE GOES AFTERWARD TO ANGERS, AND UNITES WITH THE DUKE OF ORLEANS AND THE OTHER PRINCES OF HIS PARTY. The duke of Berry, finding that he had not that government of the king and the duke of Acquitaine to which he had been accustomed, became very discontented, and retired to his estates, indignant at the ministers, and particularly at his nephew and godson, the duke of Burgundy. Shortly after, he went to Angers, where the dukes of Orleans and of Bourbon, and all the principal lords of that party, were assembled. They went in a body to the cathedral church, and there made oath, in the most solemn manner, to support each other, and mutually to defend their honour against all who should attempt any thing against it, excepting the king, and ever to remain in strict friendship united, without acting to the contrary in any kind of measure.