On Pedro's arrival at Bordeaux with his three daughters and his son, they were kindly received by the Black Prince, courtesy and kindness to those in misfortune being among the leading characteristics of his nature. Pedro, cruel and ruthless as he was, was a man of great eloquence and insinuating manners, and giving his own version of affairs, he completely won over the prince, who felt himself, moreover, bound in some degree to support him, inasmuch as he, an ally of England, had been dethroned by an army composed partly of English. Pedro made the most magnificent promises to the prince in return for his aid, ceding him the whole of the province of Biscay, and agreeing to pay the British troops engaged in his service when he regained his throne, the Black Prince engaging to pay them in the mean time. King Edward aided his son by raising an army in England, which sailed for Bordeaux under the command of the prince's brother, John of Gaunt, Duke of Lancaster. Walter formed part of this expedition. The king had issued his writs to him and other barons of the southern counties, and the Black Prince had himself written to ask him to join him, in memory of their former deeds of arms together. As it was now some years since he had taken the field, Walter did not hesitate, but with thirty retainers, headed by Ralph, joined the army of John of Gaunt. The Black Prince's first step was to endeavor to recall the Englishmen of the free companies, estimated to amount to at least thirty thousand men. The news that he was taking up arms and would himself command the army caused Calverley and the whole of the other English knights to return at once, and ten thousand of the English men-at-arms with the great companies also left Don Henry and marched to Aquitaine. The road led through the territory of the King of Navarre, and the Black Prince advanced fifty-six thousand florins of gold to pay this grasping and treacherous king for the right of passage of the army. By Christmas, 1366, the preparations were complete, but the severity of the weather delayed the advance for some weeks. Fresh difficulties were encountered with Charles the Bad, of Navarre, who, having obtained the price for the passage, had now opened negotiations with Don Henry, and the governors of the frontier towns refused to allow Sir Hugh Calverley and the free companions, who formed the advance, to pass. These were not, however, the men to stand on ceremony, and without hesitation they attacked and captured the towns, when the King of Navarre at once apologized for his officers, and renewed his engagements. As, however, the Black Prince had received intelligence that he had formed a plan for attacking the English as they passed through the terrible pass of Roncesvalles, he compelled him to accompany the army. The invitation was couched in language which was friendly, but would yet admit of no denial.