The constable of Eu, who had been taken prisoner by Edward at Caen, recovered his liberty, on the promise of delivering, as his ransom, the town of Guisnes, near Calais of which he was superior lord: but as John was offended at this stipulation, which, if fulfilled, opened still farther that frontier to the enemy, and as he suspected the constable of more dangerous connections with the king of England, he ordered him to be seized, and without any legal or formal trial, put him to death, in prison. Charles de la Cerda was appointed constable in his place; and had a like fatal end: the king of Navarre ordered him to be assassinated; and such was the weakness of the crown, that this prince, instead of dreading punishment, would not even agree to ask pardon for his offence, but on condition that he should receive an accession of territory: and he had also John's second son put into his hands, as a security for his person, when he came to court, and performed this act of mock penitence and humiliation before his sovereign.[*]
{ 1355.} The two French princes seemed entirely reconciled; but this dissimulation, to which John submitted from necessity, and Charles from habit, did not long continue; and the king of Navarre knew that he had reason to apprehend the most severe vengeance for the many crimes and treasons which he had already committed, and the still greater, which he was meditating. To insure himself of protection, he entered into a secret correspondence with England, by means of Henry, earl of Derby, now earl of Lancaster, who at that time was employed in fruitless negotiations for peace at Avignon, under the mediation of the pope. John detected this correspondence; and to prevent the dangerous effects of it, he sent forces into Normandy, the chief seat of the king of Navarre's power, and attacked his castles and fortresses. But hearing that Edward had prepared an army to support his ally, he had the weakness to propose an accommodation with Charles, and even to give this traitorous subject the sum of a hundred thousand crowns, as the purchase of a feigned reconcilement, which rendered him still more dangerous. The king of Navarre, insolent from past impunity, and desperate from the dangers which he apprehended, continued his intrigues; and associating himself with Geoffrey d'Harcourt, who had received his pardon from Philip de Valois, but persevered still in his factious disposition, he increased the number of his partisans in every part of the kingdom. He even seduced, by his address, Charles, the king of France's eldest son, a youth of seventeen years of age, who was the first that bore the appellation of "dauphin," by the reunion of the province of Dauphiny to the crown. But this prince, being made sensible of the danger and folly of these connections, promised to make atonement for the offence by the sacrifice of his associates; and in concert with his father, he invited the king of Navarre, and other noblemen of the party, to a feast at Rouen, where they were betrayed into the hands of John. Some of the most obnoxious were immediately led to execution: the king of Navarre was thrown into prison;[*] but this stroke of severity in the king, and of treachery in the dauphin, was far from proving decisive in maintaining the royal authority. Philip of Navarre, brother to Charles, and Geoffrey d'Harcourt, put all the towns and castles belonging to that prince in a posture of defence; and had immediate recourse to the protection of England in this desperate extremity.