 After Henry of Trastámara successfully seized the throne of Castile, Pedro I fled to the court of the Black Prince in Aquitaine, who began to plot his restoration by sending an army across the Pyrenees.In July 1366 Charles himself came to Bordeaux to consult with Pedro I and the Prince and agreed to keep the mountain passes of Navarre open for the passage of the army, for which he would be rewarded with the Castilian provinces of Guipúzcoa and Álava as well as additional fortresses and a large cash payment.Then in December he met Henry of Trastámara on the Navarrese border and promised instead to hold the passes closed, in return for the border town of Logroño and more cash.