The marriage served only as a cover for the imperialist ambitions of Enrique de Trastamara, who did not stop making warlike preparations and did not hesitate to resort to the bribery of some Navarrese knights. The years and the setbacks had made Don Carlos distrustful, and he did not even attend the wedding (Soria, 27-5-1375) of his first-born son with the beautiful Castilian princess. A veteran servant of the king, Don Rodrigo de Uriz, paid with his life (1376) for the sovereign's suspicions that he had secret dealings with Trastamara to give him Tudela and Caparroso. But the spark that set off the war came in France, when Charles V arrested several Navarrese dignitaries who were accompanying Prince Charles on his visit to Montpellier, Normandy and other Navarrese possessions (1378). Charles V saw - or wanted to see - the invisible hand of England behind the documentation carried by Jacques de la Rue, chamberlain of the King of Navarre, and Pierres de Utrarte. Both died under torture (21 May 1378), according to Yanguas, although the Prince of Viana also mentions Fernando de Ayanz as a victim of the French. Princes Charles, Peter and Bona were imprisoned and the Navarrese lands in France were invaded. Delachenal publishes the interrogation in which De la Rue is said to have "confessed" to the attempted poisoning of the French king (appendix, vol. III, pp. 291-293). The affair caused a new break in ties, with Castile rapidly joining the French side. Navarre lost its Provençal possessions in this war. The expulsion of the Navarrese from Normandy was not possible, however, due to the resistance of Cherbourg and English aid. Richard II of England made a pact with the Navarrese against his proverbial enemies: the French and the Castilians. On July 1, Charles II reviewed his troops in Olite. In January 1379 he camped before Soria, but failed to recover Logrono, since Pedro Manrique, Castile's adelantado in command of the fortress, betrayed him after having been bribed. Navarrese and Gascons of the garrison were taken prisoner, with Mosen Martin Enrique de Lacarra and a few others barely managing to escape. The situation worsened when Navarre was invaded by Enrique's first-born son, Don Juan. Funes, Mendavia, Larraga, Tiebas, Viana, Beriain, Villatuerta, Falces, etc. fell. For the first time in this war, the Navarrese cannons rumbled. Attacked on two fronts, Charles was unable to resist the attacks.