Editing Charles II of Navarre (section)

===Murder of Charles de la Cerda and relations with John II (1351–1356)===
Charles II served as Royal Lieutenant in Languedoc in 1351 and commanded the army which captured [[Port-Sainte-Marie]] on the [[Garonne]] in 1352. The same year he married [[Joan of Valois, Queen of Navarre|Joan of Valois]], the daughter of King [[John II of France]].{{sfn|Sumption|1999|pp=107–108}}  He soon became jealous of the Constable of France, [[Charles de La Cerda]], who was to be a beneficiary of the fiefdom of Angoulême. Charles of Navarre felt he was entitled to these territories as they had belonged to his mother, the Queen of Navarre, but they had been taken from her by the French kings for a paltry sum in compensation.{{sfn|Sumption|1999|p=103}}

After publicly quarrelling with Charles de la Cerda in Paris at Christmas 1353, Charles arranged the assassination of the Constable, which took place at the village of [[l'Aigle]] on 8 January 1354, with his brother [[Philip, Count of Longueville]] leading the murderers. Charles made no secret of his role in the murder, and within a few days was intriguing  with the English for military support against his father-in-law King John II, whose favourite the Constable had been.{{sfn|Sumption|1999|p=124–125}} John was preparing to attack his son-in-law's territories, but Charles's overtures of alliance to King [[Edward III of England]] led John to  instead make peace with Charles with the [[Treaty of Mantes]], enacted on 22 February 1354, by which Charles enlarged his possessions and was outwardly reconciled with John. The English, who had been preparing to invade France for a joint campaign with Charles against the French, felt they had been double-crossed: not for the last time, Charles had used the threat of an English alliance to wrest concessions out of the French king.
[[Image:John the Good king of Fra ordering the arrest of Charles the Bad king of Navarre.jpg|right|thumb|John the Good ordering the arrest of Charles the Bad, from the {{lang|fr|Chroniques}} of [[Jean Froissart]]]]

Relations between Charles and John once more deteriorated; in late 1354, John invaded Charles's territories in Normandy, while Charles intrigued with the [[Henry of Grosmont, 1st Duke of Lancaster|Duke of Lancaster]], serving as emissary for Edward III, at fruitless peace negotiations between England and France held in the winter of 1354–55 at [[Avignon]]. Once again, Charles changed sides: the threat of a renewed English invasion forced John to make a new agreement of reconciliation with him, which was ultimately sealed by the [[Treaty of Valognes]] on 10 September 1355.

This agreement, too, did not last. Charles befriended and was thought to be trying to influence the Dauphin—the future [[Charles V of France|Charles V]]—and was apparently involved in a botched [[coup d'état]] in December 1355, whose purpose appears to have been to replace John with the Dauphin.{{sfn|Sumption|1999|pp=199–200}} John amended matters by making his son Duke of Normandy, but Charles of Navarre continued to advise the Dauphin how to govern that province.

There were also continued rumours of his plots against the king, and on 5 April 1356 John II and a group of supporters burst unannounced into the Dauphin's castle at [[Rouen]], arrested Charles of Navarre and imprisoned him. Four of his principal supporters—two of whom had been among de la Cerda's assassins—were beheaded, and their bodies suspended from chains. Charles was taken to Paris, and once there he was moved from prison to prison for greater security.{{sfn|Sumption|1999|pp=206–207}}