That the town stood in grave need of all these warlike preparations, as well against internal disorders as against enemies from without, may be imagined from the disquieting scenes of 1356, when King John came to the castle with a hundred men-at-arms, and arrested with his own hands Charles le Mauvais, King of Navarre, and four of his suite who were falsely accused of treason. The Count of Harcourt, the Sire de Graville, Maubué de Mainnemare, and Colinet Doublet, were all beheaded on the Champ du Pardon that night in April, while the King looked on. The resistance of the citizens to this high-handed act of injustice was only quelled by the spreading of the news of the King's presence. But Philip, the brother of the King of Navarre (who had been sent to prison near Cambrai), took instant vengeance by ravaging the suburbs of Rouen, and calling in the Duke of Lancaster's English troops. It was in resisting this allied attack that the French King was beaten and taken prisoner at Poitiers. As soon as Charles le Mauvais got his freedom, two years later, he returned to rehabilitate the memory of his friends in Rouen. The body of the Count of Harcourt had been secretly removed from the public gibbet by his family. The three other corpses were taken down and borne to the Cathedral with great ceremony, where their innocence of treason was solemnly proclaimed. Excited by this open defiance of authority, the populace of the town rose against the Dauphin's men, seized the castle, and destroyed the Priory of St. Gervais with which they had a private quarrel of their own on the burning question of taxes. The commune only secured amnesty for its offences, and reconciliation with the Regent, by paying 3000 florins as a fine.
No doubt the revolt had had some obscure connection with the horrible excesses of the Jacquerie which at the same moment had been desolating Paris. The disorderly bands of ruffians who had been discharged from the French army were, at any rate, a direct source of annoyance to Rouen later on, as indeed they were to almost every town in France in that unhappy time, and Bertrand du Guesclin himself had to come to Rouen in 1364 to organise the army that finally crushed these licentious freebooters, and their ally, the King of Navarre, at Cocherel.