In the mean time, Hector and Philip de Saveuses, sir Elyon de Jacqueville, and some other captains made an excursion to Beaumont sur Oise, in the hope of gaining that pass; but it was well defended by the constable's men within the place, and they were forced to return by the town of Chambly le Haubergier, where they pillaged from churches and other places, and brought a very considerable booty to the duke their lord at Beauvais, who, a few days after, sent great part of his army to quarter themselves at Chambly and in the neighbouring villages. Shortly after, the duke departed from Beauvais with the remainder of his army,--the whole of which was so considerable that it was estimated, by those who ought to know, at sixty thousand horse. By the intrigues and solicitations of a gentleman called Charles de Mouy, the lord of Isle-Adam joined the party of the duke of Burgundy, and delivered up his town and pass to John de Fosseux, Hector and Philip de Saveuses, who placed therein, as a garrison, a sufficient number of their men at arms. When the duke was informed of this, he was very much rejoiced that the lord de l'Isle Adam had joined him, and delivered up the passage through his town. On the other hand, John de Luxembourg crossed the river Oise, with a number of men at arms which he had at Presy, in small boats, making their horses swim the river; and he quartered them at a village hard by. The morrow, he led the greater part of them to Senlis, of which town sir Robert d'Esne was bailiff for the king, having under him about sixty combatants. He made a sally with his men on foot against those of John of Luxembourg, and a grand skirmish took place. However, the majority of the commonalty of the town were not well pleased that sir Robert should thus wage war on the friends of the duke of Burgundy: and on the ensuing night, when John of Luxembourg had retreated, the townsmen rose, seized sir Robert d'Esne and all his men, after eight or ten had been killed, and carried him to prison; but through the interference of some of the principal inhabitants, he was permitted to leave the town, with his men and baggage,--and he went thence to Mont-Epiloy. The next day those of Senlis sent very early for John of Luxembourg, before whom they swore obedience to the duke of Burgundy. He received their oaths in the names of the king and duke, promising loyalty and good behaviour, and appointed Troullart de Moncruel bailiff of Senlis, with other officers according to his pleasure. When this was done, John of Luxembourg returned to the duke of Burgundy. CHAP. LX. THE DUKE OF BURGUNDY CROSSES THE RIVER OISE WITH HIS ARMY AT L'ISLE-ADAM.--HE BESIEGES AND CONQUERS BEAUMONT AND PONTOISE,--WHENCE HE REMOVES HIS QUARTERS TO L'ARBRE-SEC.