The truce with England expired in 1351, but for some years the revived hostilities were only local and unimportant. So great was the mutual exhaustion of the two states, that the new Pope, Innocent VI., elected in 1352, almost succeeded in negotiating a general peace. But, as before, it was internal disturbances in France which led to a renewal of the war. Charles of Navarre had been invested with the county of Evreux and with the large possessions of his [Sidenote: Renewed war with the English.] mother in Normandy and the Ile-de-France. He had also received in 1352 the hand of the king’s daughter, Jeanne. But his ambition was still unsatisfied, and John took no further pains to conciliate a prince who could advance claims to Champagne and Brie, and might, under favourable circumstances, become a rival candidate for the crown. In 1354 the king’s favourite, Charles of Spain, was assassinated by the emissaries of the King of Navarre. John was induced to pardon his son-in-law; but the reconciliation was only hollow, and Charles was impelled by real or imaginary grievances to open negotiations with Edward III. The English king could not resist the temptation of invading France with the aid of so powerful an ally, and prepared to enter Normandy through Calais in 1355. This danger compelled John once more to make overtures to his rebellious son-in-law, and Edward found himself deprived of the promised aid. He landed at Calais, ravaged the neighbouring districts, and then withdrew to repel a Scottish invasion. The Black Prince was more successful. Starting from Bordeaux, he marched through Languedoc, treating that province as Edward III. had treated Normandy in 1346. But the French king was as reckless as ever. Early in 1356 he surprised Charles of Navarre as he was banqueting with the Dauphin at Rouen, put his chief supporters to death, and carried the king a prisoner to Paris. The result of this violent act was to excite general disaffection. Charles’s brother, Philip of Navarre, promptly took up arms, and appealed for English support. The Black Prince was not slow to respond. His plan was to march northward through the most fertile districts of France, cross the Loire, and advance through Maine to join the rebels in Normandy. But his force was insufficient for such an enterprise. John hastily collected an army, the Loire valley was blocked, and Prince Edward had to retire before vastly superior numbers.